列车发生撞车时，列车长、运转车长应尽快向行调报告事故情况，请求（）
A.指示
B.救援
C.处理
参考答案：B
15. Great changes ______ in the city, and a lot of new buildings ______.
A．have been taken place; have been set up
B．have taken place; have been set up
C．have taken place; have set up
D．were taken place; were set up
在南极的科考工作者如果想就地解决能源问题，将来最适宜开发利用的能源是[ ]
A．水能
B．风能
C．太阳能
D．地热
