英语合并句子,并说合并理由：He looked inside. He wanted to see what they were doing?

题目

英语合并句子,并说合并理由：He looked inside. He wanted to see what they were doing?
对了，合并有限制，是He looked inside _____ ______ what they were doing. （中间之有2个空）

答案

He looked inside to see what they were doing.
表目的用to do