He spend an hour working out the math problem.的意思和同义句
问题描述：
He spend an hour working out the math problem.的意思和同义句
答
他花了一个小时来解答这道数学题An hour has been spent on the math problem by him.用It开头，中间为an hour，最后是out the。。。 这个是过去式，不好意思 spentIt took him an hour to work out the math problem.^_^这个应该怎么理解呢？额就是这样啊^_^