spend的主语必须是人1) spend time ／money on sth.在……上花费时间（金钱）.例：I spe

spend的主语必须是人
1) spend time ／money on sth.在……上花费时间（金钱）.例：I spent two hours on this maths problem.这道数学题花了我两个小时.
(2) spend time ／ money (in) doing sth.花费时间（金钱）做某事.例：They spent two years (in) building this bridge.造这座桥花了他们两年时间.
(3)spend money for sth.花钱买…….例：His money was spent for books.他的钱用来买书了.第三例子不就变成物了吗（His money 请问第三个例子正确不呢?应该如何理解.