The fundamental reason why people in general do not speak foreign languages very much better than they do is that they fail to grasp the true nature of the problem of learning to pronounce, and consequently never ______ tackling it in the right way.

A．turn to

B．insist on

C．set about

D．work at

汽车的轮矩越小，前后桥的最低点离地距离越大，则汽车的横向通过半径（）。

A.越大

B.越小

C.不变

D.越大或越小