Lack of teamwork can result in _____by rivals when we have a basketball game.  [ ]

A. defeated        

B. being defeated    

C. defeating       

D. to be defeated

造成气阀定时不正确的原因有（）。

Ⅰ.凸轮磨损

Ⅱ.滚轮磨损变形

Ⅲ.定时齿轮或链条磨损

Ⅳ.气间隙太大或太小

Ⅴ.凸轮安装不正确

Ⅵ.凸轮轴安装不正确

A．除I外全部

B．除Ⅱ外全部

C．除V外全部

D．以上全部