Some policemen were sent there to the villagers down the trees.A. keep; cuttingB. preven

问题补充：

Some policemen were sent there to the villagers down the trees.

A. keep; cutting

B. prevent; cutting

C. prevent; to cut

D. stop; to cut

答案：

A. keep; cutting

(答案→)B. prevent; cutting

C. prevent; to cut

D. stop; to cut

解析：考查短语：prevent/ stop sb /sth form doing sth ，阻止某人某物做某事，form 可以省略，keep sb /sth form doing sth也是阻止某人某物做某事，但form 不能省略。所以选B。