private cars are bringing us convenience, they also cause more traffic accidents

______ private cars are bringing us convenience, they also cause more traffic accidents and pollution.

       A. While          B. As         C. If     D. Since

试题答案

A

解析:

此题用意是考查连词的用法。两分句之间存在转折关系，而此处while 相当于although，意为”虽然”。