轮心由轮毂、轮辋、（）组成。
A.轮箍
B.轮辐
C.踏面
参考答案：A
_____________ the ability to speak, so he used sign language to communicate with others.
A．As he lost
B．He lost
C．Having lost
D．His being lost
A．expert
B．exhibition
C．exercise
D．exist
