He is __________ as a leader but he doesn’t have _________in teaching.

A．success; many experience

B．a success; much experience

C．success; an experience

D．success; a lot of experiences

圆筒型轴承的顶部间隙是椭圆型轴承的（）。

A、2倍；

B、1.5倍；

C、1倍；

D、1/2倍。