氢气干燥装置在再生过程中用的再生气是()。
A.氮气;
B.氢气;
C.二氧化碳;
D.惰性气体。
参考答案:B
The old man put his oars (船桨) in the water and _____ the smooth surface of the lake. [ ]
A. disturbed
B. interrupted
C. stopped
D. made
用于叫校正精密件角度的量具是()。
A.角度直尺
B.万能游标量角器
C.角度量块
D.正弦规