Question

4.They are going to have the serviceman ___ an electric fan

Answer 1

记住这个句型 have sb DO sth 是让某人做某事,因为DO 部分要用动词原型,而不是不定式所以不能选B .如果DO 部分用过去分词,表示让某事被做.如：have an electric fan installed.这就是have sth DONE 句型.所以不能选D.

have sb DO sth 是让某人做某事

have sth DONE 让某事被做

have to do sth 表示必须做某事

have done sth 是现在完成时的基本结构.