平曲线的基本形式有()。
A、圆曲线
B、复曲线
C、缓和曲线
D、竖曲线
参考答案:A, C
For fear of unemployment,almost one million people sat China's civil service examination in order to get
________ jobs.[ ]
A.proper
B.suitable
C.generous
D.secure
VHF双值班守听信道是(),守听时间分别是()
A.CH16和CH70;0.1s,0.9s
B.CH16和任选一非CH16;0.1s,0.9s
C.CH16和任选一非CH16;1s,9s
D.CH70和任选一非CH16;1s,9s