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。