螺纹千分尺主要用来测量螺纹的()尺寸。
A.外径
B.螺距
C.中径
D.内径
参考答案:C
The police refused to _____ the clues they were working on.
A.exhibit
B.disclose
C.expose
D.discern
往复式压缩机的传动部分一般由()构成。
A.气阀
B.气缸
C.连杆
D.曲轴
E.十字头