列车行驶速度，运人时不得超过（）m/s。
A、2
B、4
C、6
参考答案：B
推焦中途突然停电，只好等待来电后再推。
—Thank God! This school term is coming to an end!
—Yeah , after all that hard work , we all a holiday.
A．preserve
B．observe
C．reserve
D．deserve
