题目：When we desire to encourage the growth of the human spirit, we encourage the human ability to solve problems just as in school we set problems for our children 8______(solve)
答案：to solve
我的解答：to be solved
这个是set sth. for sb. to do？
这个问题不是被孩子们解决吗
to do是不定式主动式，to be done 是不定式被动式。如果能在句中找出动词不定式的执行者,则该不定式则用主动式。
在这里执行者是children。