The more people drive the traffic accidents there will be. A. careful; less B. carefully

问题补充：

The more people drive, the traffic accidents there will be.

A. careful; less B. carefully; fewer C. careful; fewer

答案：

解析：第一空修饰动词drive，要用副词carefully;句意;人们开车越认真，可能发生的事故就越少。所以选B。