They considered a computer which was considered a great help in their work.A. to buy；to

问题补充：

They considered a computer, which was considered a great help in their work.

A. to buy；to be

B. buying；being

C. to buy；being

D. buying；to be

答案：

A. to buy；to be

B. buying；being

C. to buy；being

(答案→)D. buying；to be

解析：句意：他们考虑买一台计算机，被认为是在其工作中有很大的帮助。consider vt1.考虑，+v-ing 2. 把(某人、某事)看作…，认为(某人、某事)如何〔后接 as ..., of ..., (to be) ... 等〕,根据题意可知D正确。

考点: 考查非谓语动词的用法辨析。