启动机滚柱式离合器由（）、滚柱、套筒、移动衬套、弹簧等组成。
A.驱动齿轮
B.摩擦片
C.接合鼓
D.皮带轮
参考答案：A
Can I help you? [ ]
A. I want to buy a suit for my son.
B. There is something wrong with my teeth.
C. I want to borrow a dictionary.
D. Thank you for your help.
公钥加密系统的基本组成元素是什么？
[ ]