32. Why does the author mention Concorde?
A. To suggest the rapid development of planes.
B. To stress the negative effect of sonic booms.
C. To introduce how a commercial plane is designed.
D. To show Congress’ important role in making planes.
33. What is the fourth paragraph mainly about?
A. The basic data of the new plane.
B. The working principle of the new plane.
C. The problems of the new plane.
D. The potential market of the new plane.
34. What does the underlined word “endorsement” in paragraph 5 mean?
35. What is the purpose of the passage?
A. To inform people of NASA’s new plane.
B. To prove the disadvantages of supersonic flight.
C. To explain why speed matters in supersonic flight.
D. To clarify some misunderstandings about commercial planes.