The Turners consider a computer which is commonly considered a great help in our work and

问题补充：

The Turners consider a computer, which is commonly considered a great help in our work and study.

A. to buy; to be

B. buying ; to be

C. to buy; being

D. buying; being

答案：

A. to buy; to be

(答案→)B. buying ; to be

C. to buy; being

D. buying; being

解析：考查consider用法。Consider doing sth考虑做某事；consider sb/sth to be/as…认为某人…;句意：特纳一家在考虑买一台电脑，电脑被认为是对我们的工作和学习有很大作用的。故B正确。