高压电弧温度可高达()℃。
A、1000
B、2000
C、4000
D、8000
参考答案:D
In the last few years thousands of films ________all over the word.(2011·天津)
A.have produced
B.have been produced
C.are producing
D.are being produced
夜间施工开行的工程列车,必须在压道车到达前()分钟出清正线,由施工工程列车担当压道任务时,压道路径由行车调度员指定;