If you want to be          , you’d better take           .

A．healthy enough, exercise enough

B．enough healthy, enough exercise

C．enough healthy, exercise enough

D．healthy enough, enough exercise

对飞行而言，半规管的主要缺陷是（）.

A.不能感知匀速运动，也不能感知构成合力的分力

B.不能感知俯仰加速度、只能感知偏转和滚转运动

C.只能感知重力加速度，不能感知飞机加速度