曲轴由曲轴前端、曲轴销、曲柄、主轴颈和（）组成。
A.曲轴后端
B.曲拐
C.连杆轴颈
D.连杆瓦
参考答案：A
We're looking forward to _____a chance to watch the opening ceremony of the London 2012 Olympic
Games. [ ]
A. give
B. be given
C. giving
D. being given
抽吸压力的慨念是什么？
