(D) Main Idea / Theme

In 2007, computer scientist Luis von Ahn was working on converting printed books into a digital format. He found that some words were distorted enough that digital scanners couldn’t recognize them, but most humans could easily read them. Based on that finding, von Ahn invented a simple security test to keep automated “bots” out of websites. The first version of the reCAPTCHA test asked users to type one known word and one of the many words scanners couldn’t recognize. Correct answers proved the users were humans and added data to the book-digitizing project.

Which choice best states the main purpose of thetext?

The following text is from Maggie Pogue Johnson’s1910 poem “Poet of Our Race.” In this poem, the speaker is addressing Paul Laurence Dunbar, an author.

Thou, with stroke of mighty pen,

Hast told of joy and mirth,

And read the hearts and souls of men

As cradled from their birth.

The language of the flowers,

Thou hast read them all,

And e’en the little brook

Responded to thy call.

Which choice best states the main purpose of the text?

The following text is adapted from Edith Nesbit’s1906 novel The Railway Children.

Mother did not spend all her time in paying dull[visits] to dull ladies, and sitting dully at home waiting for dull ladies to pay [visits] to her.  She was almost always there, ready to play with the children, and read to them, and help them to do their home-lessons. Besides this she used to write stories for them while they were at school, and read them aloud after tea, and she always made up funny pieces of poetry for their birthdays and for other great occasions. According to the text, what is true about Mother?

Herbivorous sauropod dinosaurs could grow more than 100 feet long and weigh up to 80 tons, and some researchers have attributed the evolution of sauropods to such massive sizes to increased plant production resulting from high levels of atmospheric carbon dioxide during the Mesozoic era. However, there is no evidence of significant spikes in carbon dioxide levels coinciding with relevant periods in sauropod evolution, such as when the first large sauropods appeared, when several sauropod lineages underwent further evolution toward gigantism, or when sauropods reached their maximum known sizes, suggesting that ______________________

Which choice most logically completes the text?

The following text is from Charlotte Brontë’s 1847 novel Jane Eyre. Jane works as a governess at Thornfield Hall.

I went on with my day’s business tranquilly; but ever and anon vague suggestions kept wandering across my brain of reasons why I should quit Thornfield; and I kept involuntarily framing advertisements and pondering conjectures about new situations: these thoughts I did not think to check; they might germinate and bear fruit if they could.

Which choice best states the main purpose of the text?

The following text is adapted from William Shakespeare’s 1609 poem “Sonnet 27.” The poem is addressed to a close friend as if he were physically present.

Weary with toil, I [hurry] to my bed,

The dear repose for limbs with travel tired;

But then begins a journey in my head

To work my mind, when body’s work’s expired:

For then my thoughts—from far where I abide—

[Begin] a zealous pilgrimage to thee,

And keep my drooping eyelids open wide,

What is the main idea of the text?

The following text is from Georgia Douglas Johnson’s 1922 poem “Benediction.”

Go forth, my son,

Winged by my heart’s desire!

Great reaches, yet unknown,

Await

For your possession.

I may not, if I would,

Retrace the way with you,

My pilgrimage is through,

But life is calling you!

Which choice best states the main purpose of the text?

In 2014, Amelia Quon and her team at NASA set out to build a helicopter capable of flying on Mars. Because Mars’s atmosphere is only one percent as dense as Earth’s, the air of Mars would not provide enough resistance to the rotating blades of a standard helicopter for the aircraft to stay aloft. For five years, Quon’s team tested designs in a lab that mimicked Mars’s atmospheric conditions. The craft the team ultimately designed can fly on Mars because its blades are longer and rotate faster than those of a helicopter of the same size built for Earth.

According to the text, why would a helicopter built for Earth be unable to fly on Mars?

In West Africa, jalis have traditionally been keepers of information about family histories and records of important events. They have often served as teachers and advisers, too. New technologies may have changed some aspects of the role today, but jalis continue to be valued for knowing and protecting their peoples’ stories.

Which choice best states the main idea of the text?

In 1934 physicist Eugene Wigner posited the existence of a crystal consisting entirely of electrons in a honeycomb-like structure. The so-called Wigner crystal remained largely conjecture, however, until Feng Wang and colleagues announced in 2021 that they had captured an image of one. The researchers trapped electrons between two semiconductors and then cooled the apparatus, causing the electrons to settle into a crystalline structure. By inserting an ultrathin sheet of graphene above the crystal, the researchers obtained an impression—the first visual confirmation of the Wigner crystal.

Which choice best states the main idea of the text?