—I hear you have to exercise early in the morning.

—Right. It's one of the        in my family.[ ]

A. plans  

B. members  

C. rules      

D. suggestions

机动车之所以能对外作功，四行程发动机的（）是不可缺少的。

A.旋转行程

B.作功行程

C.上行程

D.下行程