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BOOST Part One
Quiz by Shelly Markowitz
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What is there to eat?
Do you mind?
I'm so hungry!
Good morning
You have more presents than me.
Once upon a time.
That's not fair!
Are you ready?
Give this quiz to my class
What is there to eat?
You have more presents than me.
The party will start in five minutes.
That city is dangerous.
My bicycle broke!
Hello Chuxing, one of China’s top bike-sharing platforms backed by ecommerce giant Alibaba Group Holding, has applied to go public on the Nasdaq stock exchange. Launched in 2016, Hello Chuxing gained traction quickly as the first bikesharing operator to focus its business within China’s smaller cities and towns. It managed to survive China’s bike-sharing bubble between 2017 and 2018 when Ofo went into bankruptcy and Mobike was acquired by Meituan. The “survivor” had more than 10 million bicycles operating in over 400 Chinese cities as of December 2020. Hello Chuxing is developing its new business aggressively. In 2019, it took on sector leader Didi Chuxing with a new business Hello Dache that provides car-sharing and carpooling services. It has also been following industry giant Meituan into the life services field with new “intra-city logistics” and “bulk buying” services. The service, Hello Dache, features instant communication that enables passengers to keep in touch with drivers online once ride requests have been accepted. It also features a one-click button to call the police as part of efforts to boost safety. It is now looking into travel, with the aim of being a travel-based platform that provides daily life services, a person familiar with the matter said. “The market was too lavish when capital players and consumers were optimistic about the sector,” founder Yang Lei said back in 2019. “Firms would burn through cash subsidies to keep up with rivals and maintain a rapid pace of expansion. Hello Chuxing, however, has been careful to watch every penny and use money wisely while planning for the future,” he said.
“There’s No Such Thing as Sound Science” by By Christie Aschwanden was a lead science writer for FiveThirtyEight. FiveThirtyEight, Science, Dec. 6, 2017 Science is being turned against itself. For decades, its twin ideals of transparency and rigor have been weaponized by those who disagree with results produced by the scientific method. Under the Trump administration, that fight has ramped up again. In a move ostensibly meant to reduce conflicts of interest, Environmental Protection Agency Administrator Scott Pruitt has removed a number of scientists from advisory panels and replaced some of them with representatives from industries that the agency regulates. Like many in the Trump administration, Pruitt has also cast doubt on the reliability of climate science. For instance, in an interview with CNBC, Pruitt said that “measuring with precision human activity on the climate is something very challenging to do.” Similarly, Trump’s pick to head NASA, an agency that oversees a large portion the nation’s climate research, has insisted that research into human influence on climate lacks certainty, and he falsely claimed that “global temperatures stopped rising 10 years ago.” Kathleen Hartnett White, Trump’s nominee to head the White House Council on Environmental Quality, said in a Senate hearing last month that she thinks we “need to have more precise explanations of the human role and the natural role” in climate change. The same entreaties crop up again and again: We need to root out conflicts. We need more precise evidence. What makes these arguments so powerful is that they sound quite similar to the points raised by proponents of a very different call for change that’s coming from within science. This other movement strives to produce more robust, reproducible findings. Despite having dissimilar goals, the two forces espouse principles that look surprisingly alike: Science needs to be transparent. Results and methods should be openly shared so that outside researchers can independently reproduce and validate them. The methods used to collect and analyze data should be rigorous and clear, and conclusions must be supported by evidence. These are the arguments underlying an “open science” reform movement that was created, in part, as a response to a “reproducibility crisis” that has struck some fields of science.1 But they’re also used as talking points by politicians who are working to make it more difficult for the EPA and other federal agencies to use science in their regulatory decision-making, under the guise of basing policy on “sound science.” Science’s virtues are being wielded against it. What distinguishes the two calls for transparency is intent: Whereas the “open science” movement aims to make science more reliable, reproducible and robust, proponents of “sound science” have historically worked to amplify uncertainty, create doubt and undermine scientific discoveries that threaten their interests. “Our criticisms are founded in a confidence in science,” said Steven Goodman, co-director of the Meta-Research Innovation Center at Stanford and a proponent of open science. “That’s a fundamental difference — we’re critiquing science to make it better. Others are critiquing it to devalue the approach itself.” Calls to base public policy on “sound science” seem unassailable if you don’t know the term’s history. The phrase was adopted by the tobacco industry in the 1990s to counteract mounting evidence linking secondhand smoke to cancer. A 1992 Environmental Protection Agency report identified secondhand smoke as a human carcinogen, and Philip Morris responded by launching an initiative to promote what it called “sound science.” In an internal memo, Philip Morris vice president of corporate affairs Ellen Merlo wrote that the program was designed to “discredit the EPA report,” “prevent states and cities, as well as businesses from passing smoking bans” and “proactively” pass legislation to help their cause. The sound science tactic exploits a fundamental feature of the scientific process: Science does not produce absolute certainty. Contrary to how it’s sometimes represented to the public, science is not a magic wand that turns everything it touches to truth. Instead, it’s a process of uncertainty reduction, much like a game of 20 Questions. Any given study can rarely answer more than one question at a time, and each study usually raises a bunch of new questions in the process of answering old ones. “Science is a process rather than an answer,” said psychologist Alison Ledgerwood of the University of California, Davis. Every answer is provisional and subject to change in the face of new evidence. It’s not entirely correct to say that “this study proves this fact,” Ledgerwood said. “We should be talking instead about how science increases or decreases our confidence in something.” The tobacco industry’s brilliant tactic was to turn this baked-in uncertainty against the scientific enterprise itself. While insisting that they merely wanted to ensure that public policy was based on sound science, tobacco companies defined the term in a way that ensured that no science could ever be sound enough. The only sound science was certain science, which is an impossible standard to achieve. “Doubt is our product,” wrote one employee of the Brown & Williamson tobacco company in a 1969 internal memo. The note went on to say that doubt “is the best means of competing with the ‘body of fact’” and “establishing a controversy.” These strategies for undermining inconvenient science were so effective that they’ve served as a sort of playbook for industry interests ever since, said Stanford University science historian Robert Proctor. The sound science push is no longer just Philip Morris sowing doubt about the links between cigarettes and cancer. It’s also a 1998 action plan by the American Petroleum Institute, Chevron and Exxon Mobil to “install uncertainty” about the link between greenhouse gas emissions and climate change. It’s industry-funded groups’ late-1990s effort to question the science the EPA was using to set fine-particle-pollution air-quality standards that the industry didn’t want. And then there was the more recent effort by Dow Chemical to insist on more scientific certainty before banning a pesticide that the EPA’s scientists had deemed risky to children. Now comes a move by the Trump administration’s EPA to repeal a 2015 rule on wetlands protection by disregarding particular studies. (To name just a few examples.) Doubt merchants aren’t pushing for knowledge, they’re practicing what Proctor has dubbed “agnogenesis” — the intentional manufacture of ignorance. This ignorance isn’t simply the absence of knowing something; it’s a lack of comprehension deliberately created by agents who don’t want you to know, Proctor said.2 In the hands of doubt-makers, transparency becomes a rhetorical move. “It’s really difficult as a scientist or policy maker to make a stand against transparency and openness, because well, who would be against it?” said Karen Levy, researcher on information science at Cornell University. But at the same time, “you can couch everything in the language of transparency and it becomes a powerful weapon.” For instance, when the EPA was preparing to set new limits on particulate pollution in the 1990s, industry groups pushed back against the research and demanded access to primary data (including records that researchers had promised participants would remain confidential) and a reanalysis of the evidence. Their calls succeeded and a new analysis was performed. The reanalysis essentially confirmed the original conclusions, but the process of conducting it delayed the implementation of regulations and cost researchers time and money. Delay is a time-tested strategy. “Gridlock is the greatest friend a global warming skeptic has,” said Marc Morano, a prominent critic of global warming research and the executive director of ClimateDepot.com, in the documentary “Merchants of Doubt” (based on the book by the same name). Morano’s site is a project of the Committee for a Constructive Tomorrow, which has received funding from the oil and gas industry. “We’re the negative force. We’re just trying to stop stuff.” Some of these ploys are getting a fresh boost from Congress. The Data Quality Act (also known as the Information Quality Act) was reportedly written by an industry lobbyist and quietly passed as part of an appropriations bill in 2000. The rule mandates that federal agencies ensure the “quality, objectivity, utility, and integrity of information” that they disseminate, though it does little to define what these terms mean. The law also provides a mechanism for citizens and groups to challenge information that they deem inaccurate, including science that they disagree with. “It was passed in this very quiet way with no explicit debate about it — that should tell you a lot about the real goals,” Levy said. But what’s most telling about the Data Quality Act is how it’s been used, Levy said. A 2004 Washington Post analysis found that in the 20 months following its implementation, the act was repeatedly used by industry groups to push back against proposed regulations and bog down the decision-making process. Instead of deploying transparency as a fundamental principle that applies to all science, these interests have used transparency as a weapon to attack very particular findings that they would like to eradicate. Now Congress is considering another way to legislate how science is used. The Honest Act, a bill sponsored by Rep. Lamar Smith of Texas,3 is another example of what Levy calls a “Trojan horse” law that uses the language of transparency as a cover to achieve other political goals. Smith’s legislation would severely limit the kind of evidence the EPA could use for decision-making. Only studies whose raw data and computer codes were publicly available would be allowed for consideration. That might sound perfectly reasonable, and in many cases it is, Goodman said. But sometimes there are good reasons why researchers can’t conform to these rules, like when the data contains confidential or sensitive medical information.4 Critics, which include more than a dozen scientific organizations, argue that, in practice, the rules would prevent many studies from being considered in EPA reviews.5 It might seem like an easy task to sort good science from bad, but in reality it’s not so simple. “There’s a misplaced idea that we can definitively distinguish the good from the not-good science, but it’s all a matter of degree,” said Brian Nosek, executive director of the Center for Open Science. “There is no perfect study.” Requiring regulators to wait until they have (nonexistent) perfect evidence is essentially “a way of saying, ‘We don’t want to use evidence for our decision-making,’” Nosek said. Most scientific controversies aren’t about science at all, and once the sides are drawn, more data is unlikely to bring opponents into agreement. Michael Carolan, who researches the sociology of technology and scientific knowledge at Colorado State University, wrote in a 2008 paper about why objective knowledge is not enough to resolve environmental controversies. “While these controversies may appear on the surface to rest on disputed questions of fact, beneath often reside differing positions of value; values that can give shape to differing understandings of what ‘the facts’ are.” What’s needed in these cases isn’t more or better science, but mechanisms to bring those hidden values to the forefront of the discussion so that they can be debated transparently. “As long as we continue down this unabashedly naive road about what science is, and what it is capable of doing, we will continue to fail to reach any sort of meaningful consensus on these matters,” Carolan writes. The dispute over tobacco was never about the science of cigarettes’ link to cancer. It was about whether companies have the right to sell dangerous products and, if so, what obligations they have to the consumers who purchased them. Similarly, the debate over climate change isn’t about whether our planet is heating, but about how much responsibility each country and person bears for stopping it. While researching her book “Merchants of Doubt,” science historian Naomi Oreskes found that some of the same people who were defending the tobacco industry as scientific experts were also receiving industry money to deny the role of human activity in global warming. What these issues had in common, she realized, was that they all involved the need for government action. “None of this is about the science. All of this is a political debate about the role of government,” she said in the documentary. These controversies are really about values, not scientific facts, and acknowledging that would allow us to have more truthful and productive debates. What would that look like in practice? Instead of cherry-picking evidence to support a particular view (and insisting that the science points to a desired action), the various sides could lay out the values they are using to assess the evidence. For instance, in Europe, many decisions are guided by the precautionary principle — a system that values caution in the face of uncertainty and says that when the risks are unclear, it should be up to industries to show that their products and processes are not harmful, rather than requiring the government to prove that they are harmful before they can be regulated. By contrast, U.S. agencies tend to wait for strong evidence of harm before issuing regulations. Both approaches have critics, but the difference between them comes down to priorities: Is it better to exercise caution at the risk of burdening companies and perhaps the economy, or is it more important to avoid potential economic downsides even if it means that sometimes a harmful product or industrial process goes unregulated? In other words, under what circumstances do we agree to act on a risk? How certain do we need to be that the risk is real, and how many people would need to be at risk, and how costly is it to reduce that risk? Those are moral questions, not scientific ones, and openly discussing and identifying these kinds of judgment calls would lead to a more honest debate. Science matters, and we need to do it as rigorously as possible. But science can’t tell us how risky is too risky to allow products like cigarettes or potentially harmful pesticides to be sold — those are value judgements that only humans can make.
Broken windows are covered. Floorboards are patched and doors screwed back on. The road that was ruined by German tanks is shovelled and raked smooth. Boot-shaped bruises turn yellow then fade and disappear. Flowers grow and spread across the ugly German footprints stomped into garden beds. The village looks pretty once more. School stops for the summer and everyone is put to work on the kolkhoz, the village farm. Women and big boys begin harvesting the barley crops in the outer fields. The biggest girls milk the cows, morning and night, and keep the barns clean. Old Nikolay mends ploughs, horse harnesses, pitchforks and scythes in his workshop. Anna Pushinka teaches Yelena and her friends how to get the honey from the beehives that are scattered through the orchards. I am in charge of collecting eggs. My friends Olga and Nina help. Olga and Nina are five, a year younger than me. They are twins and look exactly alike, except Nina’s nose is a little bit crooked from when she fell out of bed and squashed it sideways on the floor. The hens, ducks and geese wander free in the summer, so collecting eggs is like a treasure hunt and takes hours. Catching the hens for their daily hugs takes even longer, but I think it’s important because hugs make everyone happy and happy hens lay bigger eggs. Olga says I’m the best hen-hugger in all of Russia. Nina says I’ll be the best cow-hugger, too, when my arms grow longer. But good hugs have nothing to do with the size of your arms. It’s all to do with the size of your heart. When we are done with the hens, Olga, Nina and I can spend the rest of the day doing whatever we like. We climb the apricot trees, chase squirrels, lie in the meadow marvelling at how hot Ushanka’s black fur becomes in the sunshine, make daisy chains and race little boats of bark in the stream. I teach Olga and Nina the alphabet and we use charcoal to write our letters and our names all over the village – on doors and walls and the freshly cut ends of firewood. In between, I practise my knots. In case the German princemonsters return. I slip into Old Nikolay’s workshop and tie knots in the harnesses hanging on the walls. I wander into gardens where the washing is hung out to dry and tie knots in the laces on pants and smocks. I creep up behind Anna Pushinka and tie knots in her apron strings. I find baling twine in the hay shed and tie my own ankles together. I do such a good job of these last knots that I can’t get them undone. I have to jump all the way to Olga and Nina’s house and ask them to cut me free with their mama’s knife. At the end of each day, Ushanka and I run out into the distant barley fields to meet Mama. This is my favourite part of the day, because Mama always shouts, ‘Little Rabbit!’ and smothers my head with kisses. And as we walk home, we sing. Everyone – women, big boys and me. I love to sing. Almost as much as I love to be kissed by Mama. Sometimes one of the boys, Mikhail, has his balalaika with him. He takes the instrument out from beneath the sheaves of barley piled high on the wagon and plays music. We sing about forests and orchards and people who find their true love. As we walk home, arm in arm, my heart fills with happiness and my belly swells with pride that I am allowed to sing along with the big boys. And I can almost forget about the German prince-monsters and their lies about Russia and their big ugly boots. Almost. But today, when Mikhail reaches for his balalaika, I see other things hiding beneath the barley sheaves. Three of the mamas rush forward and cover them up, but it’s too late. I know they are there. I’ve already seen them. Rifles. Lots of rifles. Mikhail hugs his balalaika to his chest and blushes. ‘So play!’ cries Mama, her voice oddly loud and high. ‘Let’s play Sasha’s favourite song, “The Little Birch Tree”.’ So Mikhail plays and everyone sings about the lovely birch tree with its curly leaves and the branches that will be turned into silver flutes. They sing too quickly, too loudly, and as they sing and walk, they cast nervous sideways glances at me. ‘It’s alright,’ I say, when the song comes to an end. ‘I didn’t see the rifles.’ Mama nods and smiles, and I know it was the right thing to say. But I did see the rifles. And I think about Yelena wanting to get lots of guns and dynamite for the Partisans so they can shoot the Germans and blow them into thousands of tiny pieces, and Mama looking as though she agreed, and I know this is what the mamas and the big boys are doing. As well as harvesting, they are helping the Partisans. Three days later, I wake before dawn and I am all alone. Yelena is always here beside me when I wake. But not this morning. I climb down from our bed above the stove. Mama is filling a cloth sack with bread. She ties it closed with a piece of string and hands it to Yelena. ‘Stay out of sight,’ says Mama. ‘And don’t return until after dark.’ ‘Where’s she going?’ I ask. ‘Nowhere,’ snaps Mama. ‘Then why does she need all that bread?’ I ask. ‘There’s nothing left for us.’ Mama baked four loaves last night and she has stuffed them all into the sack. Yelena opens her mouth, but before she can speak, Mama shoves her out the door and sends her on the way to nowhere. Mama turns and stares at me, her blue, blue cornflower eyes wide with worry. ‘I know,’ I say, flopping down on the bench. ‘I didn’t see any bread.’ Mama sits beside me and takes my hand. ‘And . . .?’ she prods, obviously waiting for more. I puzzle for a while, then say, ‘And I don’t have a sister called Yelena.’ Mama laughs, softly and with a little bit of sadness around the edges. ‘Sweet Little Rabbit! You do have a sister called Yelena.’ ‘I do?’ I ask, now confused. ‘I haven’t seen the rifles or the bread, but I have seen Yelena?’ ‘Yes.’ Mama smiles and the magic makes me smile, too. And I am glad that Yelena is real because I love her very much. ‘Yelena is real,’ Mama explains, ‘but she does not carry sacks of bread into the forest for the Partisans.’ ‘Of course not!’ I shout, slapping my forehead. ‘Because there is no bread!’ Mama laughs loudly now, with not a hint of sadness. She hugs me, pressing me against her warm, loving heart, covering my head with kisses. ‘Clever Little Rabbit,’ she murmurs, and then, in barely a whisper, ‘Your papa would be so proud.’ When I wake the next morning, Yelena is sleeping beside me, her mouth open, her braided hair unravelling. Mama is serving kasha to a strange woman seated at our table. I crawl down from above the stove and slide along the bench beside her. I stare at her pants, her tunic, the rope she is using as a belt and her big boots. She’s dressed like a man! And there’s a rifle leaning against the wall near the door. ‘Hello,’ I say. ‘I’m Sasha.’ The woman doesn’t reply. She just shovels down her kasha. I line my four wooden bears along the table in front of her bowl and say, ‘These are my bears: Big Bear, Medium Bear, Little Bear and Even Littler Bear.’ ‘Hello, Sasha. Hello, bears.’ She smiles but she doesn’t tell me her name. ‘Why are you dressed like a man?’ I ask, tugging at the sleeve of her tunic. ‘Because men’s clothes make it easier to run and climb and crawl and shoot,’ she says. ‘You’re a Partisan!’ I gasp. ‘But she’s not real,’ says Mama, placing a bowl of kasha before me. ‘Is the kasha real?’ I ask. Mama laughs. ‘Yes, Little Rabbit.’ I’m glad the food is real, because I’m hungry. But I’m disappointed that the woman is not real. I was going to ask if I could use her rope-belt to tie her ankles together. For practice. But if she’s not real, then the rope and her ankles aren’t either. The woman finishes her kasha, hangs her rifle over her shoulder, kisses Mama on the cheek then slips out the door. I run to the window to watch her leave, but by the time I get there, she’s gone. Vanished. ‘Because she’s not real,’ I whisper. A week later, Mama and I are working in the garden. We sing as we weed between the flowers and pluck caterpillars from the vegetables. Anna Pushinka is picking strawberries in her garden and wanders over. ‘Taste these,’ she says, holding out the basket. Mama reaches in and takes out a fat strawberry and a tiny piece of folded paper. The strawberry goes into her mouth, the paper into her pocket. ‘What’s on the paper?’ I ask. ‘Paper?’ Anna Pushinka replies with a wave of her hand. ‘Goodness, Sasha! Who has money for paper? These are lean times. We must choose between paper for writing and noodles for our soup. And I always choose noodles.’ She chuckles and I know the paper is yet another thing that is not real. That night, Mama slips the paper to Yelena, but she drops it on the floor. I pick it up for her, and I see that there are tiny words and numbers written all over it. I wish I could read better. I’m desperate to know what it says. Or rather, what it doesn’t say, because it’s not real. Later, when Mama has tucked us into our bed above the stove and Ushanka has wrapped herself around the top of my head, I ask Yelena, ‘What’s on the paper?’ ‘What paper?’ says Yelena. ‘The paper that isn’t real,’ I reply. Yelena stares at me, nibbling her lip, then whispers, ‘A message for the Partisans. Stuff about where the Germans have their headquarters and when their trains are travelling and where they store their ammunition.’ ‘Why?’ ‘So the Partisans can blow them up.’ Yelena grabs my arm. ‘But don’t tell anyone. It’s a secret.’ ‘What’s a secret?’ I ask. ‘The message.’ ‘What message?’ I say, my eyes wide. Yelena laughs. ‘Good boy, Sasha.’ My belly swells with pride. I know how to play this game. ‘How are your knots coming along?’ asks Yelena. ‘Good! Yesterday, I crept into the dairy and tied knots in the apron strings of all the girls who were milking and only one of them noticed. Today, I tied Olga’s ankles together with Mama’s embroidery thread and just now, while you were taking a bath, I tied the sleeves of your blouse together in an enormous knot.’ Yelena rolls her eyes, then says, ‘I’ll see if I can find you some rope for practising.’ ‘Practising what?’ I ask. ‘Your knots,’ she says. ‘What knots?’ Yelena, my big sister who is twelve and always serious t
Camshaft: A rotating shaft in an engine that controls the opening and closing of the intake and exhaust valves. Aftercooler (air to air): A device that cools the compressed air from a turbocharger using outside air. Glow Plugs: Heating elements used to aid in starting diesel engines in cold temperatures. Timing Cover: The cover that protects the timing gears and belt or chain in an engine. Exhaust Manifold: A component that collects exhaust gases from multiple cylinders and directs them to the exhaust pipe. Oil Suction Tube: A tube that draws oil from the oil pan to the oil pump. Air Compressor: A device that increases the pressure of air and is often used to power air brakes or pneumatic tools. Oil Cooler: A device that cools the engine oil, helping prevent it from overheating. Supercharger/Blower: A device that increases the pressure of the air-fuel mixture entering the engine to boost power. Piston Rings: Rings around the piston that seal the combustion chamber, control oil consumption, and conduct heat. Crankshaft: A shaft that converts the linear motion of the pistons into rotational motion to power the vehicle. Oil Pan: A reservoir at the bottom of the engine that collects and holds the engine oil. Connecting Rod: Connects the piston to the crankshaft, converting the piston's motion into rotational motion. Stroke: The distance the piston travels within the cylinder, from top dead center to bottom dead center. 2 Cycle: A type of engine that completes a power cycle in two strokes of the piston. Crankshaft Main Bearing: The bearing that supports the crankshaft in the engine block. Aftercooler (water/coolant): A device that cools the compressed air from a turbocharger using water or coolant. Water Pump: A pump that circulates coolant through the engine and radiator to prevent overheating. Oil Filter: A filter that removes contaminants from the engine oil. Vibration Dampener: A device attached to the crankshaft to reduce engine vibrations. Piston Wrist Pin: The pin that connects the piston to the connecting rod. Valve Cover: The cover that protects the engine's valves and camshaft. Cylinder Block: The main structure of an engine that houses the cylinders and other components. ECM/ECU: Electronic Control Module or Electronic Control Unit, which controls various engine functions. Cylinder Head: The top part of the cylinder that contains the combustion chamber, valves, and spark plugs. Oil Pump: A pump that circulates oil through the engine to lubricate moving parts. Cylinder Liner: A sleeve inside the cylinder that protects it from wear and corrosion. TDC (Top Dead Center): The highest position the piston reaches in its stroke. Bore: The diameter of a cylinder in an engine. Flywheel: A heavy wheel that stores rotational energy to smooth out engine operation. Crankshaft Rod Bearing: The bearing that connects the crankshaft to the connecting rod. Push Tube / Push Rod: Rods that transmit motion from the camshaft to the valves. Piston: A cylindrical component that moves up and down within the cylinder to create power. Flywheel Housing: The casing that surrounds and supports the flywheel. Valve Lifter or Cam Follower: A component that follows the camshaft lobes to open and close the valves. Turbo: A device that increases the engine’s power by forcing more air into the combustion chamber. Intake & Exhaust Valves: Valves that control the intake of air and the exhaust of gases in the engine. Intake Manifold: A manifold that distributes the air-fuel mixture or air to the cylinders. Rocker Arm: A lever that transfers camshaft motion to the valves. Wastegate: A valve that controls the exhaust gases flowing to the turbocharger, preventing excessive boost pressure. Fuel Injector: A device that sprays fuel into the combustion chamber. Fuel Pump: A pump that moves fuel from the fuel tank to the engine. BDC (Bottom Dead Center): The lowest position the piston reaches in its stroke. 4 Cycle: A type of engine that completes a power cycle in four strokes (intake, compression, power, exhaust). Articulated Piston: A piston with two pieces (crown and skirt) joined by a pivot, allowing some flexibility in movement.
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