They considered a puter, 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
网友回答
A. to buy; to be
B. buying; being
C. to buy; being
(答案→)D. buying; to be
解析：考查动词consider 的用法:考虑做某事 consider doing, 被认为 be considered to be ,根据题意应选D 。