there are many problems to solve 还是 to be solved 解释一下不定式什么时候用主动什么时候用被动

问题描述:

there are many problems to solve 还是 to be solved 解释一下不定式什么时候用主动什么时候用被动

这句是to be solved
是I solve problems
主动式I have so many problems to solve.
被动式 there are many problems to be solved