客车辅修按周期定期施行，主要是施行（）检查和滚动轴承轴箱检查。
参考答案：制动装置
The novel written by the author ________ best, but five years ago no one could have imagined how great a role he ________ in the literary world.
A．sells; was to play
B．was selling; was playing
C．sold; had played
D．is sold; is playing
塑料管焊接，当管径小于200mm时，一般应采用的焊接形式为（）。
A.气压焊
B.承插口焊接
C.等离子弧焊
D.对焊焊接
