题目内容：

A: What are you doing, Linda?

B: 1.

A: An experiment? What is it about?

B: A theory about air pressure. I fill a jar with water. I cover the top with a piece of cardboard. Then, I turn the jar upside down.2.

A: I think we can’t do it inside. I’m sure that the floor will get wet.

B: No,3.

A: Why? The water won’t stay in the jar.

B:4. .

A: Great!5. .