用适当的介词完成下列句子1.Mr Brown is busy ( ) his work 2.The boy has a bad cold .please send ( ) a doctor at once 3.What should we do ( )[relax]?
问题描述：
用适当的介词完成下列句子
1.Mr Brown is busy ( ) his work
2.The boy has a bad cold .please send ( ) a doctor at once
3.What should we do ( )[relax]?
答
1、with
2、for
3、to（动词不定式）
答
1. on 2.to 3.for
答
1.with be busy with sth 固定搭配
2.for sent for 派人去请医生来
3.to 表目的 用to