— How long have you stayed here?
— ______ two days. [ ]
A. For
B. In
C. By
D. To
答案:A
铸造金属全冠面磨除的厚度最少为()
A.0.1mm
B.0.2mm
C.0.3mm
D.0.5mm
E.1.0mm
铁路粘油罐车的卸油作业采用()。
A、潜油泵卸油
B、自流卸油
C、压力卸油
D、下部卸油