救援列车因路内、外单位工作需要短期使用时,须报经铁路局批准,并由铁路局()发布命令。
A、机务段值班员
B、列车调度员
C、机车调度员
D、路局局长
参考答案:C
.This summer she took a training course, which was to help people develop their reading skills.
A.operated
B.devoted
C.designed
D.furnished
碳钢的可焊性随含碳量的高低而不同,低碳钢焊后()。
A、强度增加,淬脆倾向变大;
B、焊缝易生气孔;
C、出现裂纹;
D、缺陷少。