Questions 23 to 25 are based on the conversation you have just heard.

A. She paid by check.
B. She decided to make the purchase.
C. She paid by credit card.
D. She left without paying.

A. To find out how much air can be pumped into a plane.
B. To find out how much air passengers need to breathe at certain altitudes.
C. To find what would happen if the plane crashed in the water.
D. To find out if there are any weak parts in the plane that would burst under pressure.