在道路上跟车行驶时，跟车距离不是主要的，只须保持与前车相等的速度，即可防止发生追尾事故。
参考答案：错
He _____ the club and _____ its activities.
A．took part in; joined
B．joined; took part in
C．joined; took a part in
D．took part in; took part in
“人”字型复轨器尾部导轮棱的有效跨度为（）mm。
A.200
B.220
C.240
D.260
