Some of the engines were not suitable for the work they were for.A. intendedB. to intendC

问题补充：

Some of the engines were not suitable for the work they were for.

A. intended

B. to intend

C. intending

D. being intended

答案：

(答案→)A. intended

B. to intend

C. intending

D. being intended

解析：考查语态。句意：一些引擎不适合他们意向的工作。结合句意可知the work是intendfor的动作对象，故用被动语态，选A。