12. Helicopters work with the aid of ________.
[A] a combination of rotating devices in front and on top
[B] a rotating device topside
[C] one rotating fan in the center of the aircraft and others at each end
[D] a rotating fan underneath for lifting
13. What is said about the development of the helicopter?
[A] Helicopters have only been worked on by man since 1940.
[B] Chinese children were the first to achieve flight in helicopters.
[C] Helicopters were considered more dangerous than the early airplanes.
[D] Some people thought they would become widely used by average individuals.
14. How has the use of helicopters developed?
[A] They have been widely used for various purposes.
[B] They are taking the place of high-flying jets.
[C] They are used for rescue work.
[D] They are now used exclusively for commercial projects.
15. Under what conditions are helicopters found to be absolutely essential?
[A] For overseas passenger transportation.
[B] For extremely high altitude flights.
[C] For high-speed transportation.
[D] For urgent mission to places inaccessible to other kinds of craft.
【1987年考研英语阅读真题及答案解析】相关文章:
★ 2014年12月英语六级阅读理解真题训练:University
最新
2016-10-18
2016-10-11
2016-10-11
2016-10-08
2016-09-30
2016-09-30