— I'm sure I will get good grades (成绩) in the graduation exam.
— If so, I believe your parents will ______ the result.

A. be satisfied with
B. be angry about
C. be bored of
D. be worried about

在火炬信号前停车后，列车以在隙望距离内能随时停车的速度继续运行，在半自动闭塞区间，经过（）后可恢复正常速度运行。

A.1km

B.2km

C.3km

D.5km