Wang Gang is considering buying a computer is considered to be a great help in our work a

问题补充：

Wang Gang is considering buying a computer, is considered to be a great help in our work and study.

A. as

B. which

C. that

D. what

答案：

A. as

(答案→)B. which

C. that

D. what

解析： 考查非限制性定语从句。先行词是a computer，在从句中作主语，as正如，正像，不符合句意；that不能引导非限制性定语从句；what不能引导定从。所以选B。