检修顺序控制盘需关闭（）后放空。
A.压缩机
B.高压储气装置
C.加气机
D.压缩机及高压储气装置
参考答案：D
If he _____ , I _____ swimming alone.
[ ]
A. doesn't come, will go
B. won't come, will go
C. will come, won't go
D. is coming, don't go
锯黄铜时应选用的（）的锯条。
A.粗锯齿
B.细锯齿
C.中锯齿
D.粗或中锯齿
