听觉信号不包括（）。
A.号角、口笛发出的音响
B.放置响墩地点标
C.机车、轨道车的鸣笛声
D.响墩发出的音响
参考答案：B
If all the people _______ kind and honest, the world _______a better place to live in. [ ]
A. are; will be
B. were; will be
C. were; would be
D. were; should be
——Did you inform Helen of the plan put forward at the meeting?
—Of course. ________ I saw her.
A．So long as
B．If only
C．The moment
D．Any time
