Timmy: What are you doing, Jack? Jack: I am making lemonade. I will sell lemonade at my lemonade stand. Timmy: How does it taste? Is it delicious? Jack: I don't know. This is my first time to make lemonade. Timmy: Here, you can have a try. Jack: Wow, this is not very yummy. It tastes just like lemon juice. It is very sour. Timmy: You need to add sugar. Here, have a taste. Jack: Wow, this tastes very sweet. It's yummy! Thanks, Timmy!