卧式镗床下滑座镶条过紧或蜗杆副间隙过小，都全使其在低速运转时产生爬行。
参考答案：对
A government official was murdered last Friday and the police are collecting information that is________
to the case.[ ]
A. relevant
B. similar
C. devoted
D. addicted
The customs duties act _______ an essential leverage on regulating import and export behavior.
A．at B．asC．in D．to
