— How far is your cousin's home from here?

— It's about two _____ drive.[ ]

A. hour's

B. hours

C. hours'

D. hour

三角高程测量是根据已知点高程及两点间的（）确定未知点高程的测量方法。

A.水平距离和水平角

B.水平距离和竖直角

C.高差和水平角

D.水平距离和高差