The science of computer, _____rapid progress has been made in recent years, is the most important of all science.

A．to which

B．in which

C．of which

D．from which

下列原因使用静变流机（）

A.APU起动（给燃油泵供电）；

B.冲压空气涡轮放出；

C.用电瓶起动发动机（点火）。