The air cycle machine consists of a_____ (涡轮) and a ______ (压气机)

The air cycle machine consists of a_____ (涡轮) and a ______ (压气机)mounted on a common shaft.

A.turbine wheel,compressor wheel

B.compressor wheel,turbine wheel

C.left pack,right pack

D.right pack,left pack

正确答案是A