活塞环对口、抱死，若注油后将（）窜气甚至更甚。
A.冒烟
B.冒气
C.消失
参考答案：A
He does help others, but he always expects returns ____. As a result, nobody will accept anything from him.
A．at no time
B．in no time
C．for no time
D．after no time
21T轴重提速货车转向架包括
A.K2
B.K5
C.K7
