cost的主语是物或某种活动, 还可以表示“值”, 常见用法如下：(1)sth. costs (sb.) ＋金钱,某物花了（某人）多少钱.例：A new computer costs a lot of money. 买一台新电脑要花一大笔钱.(2) (doing) sth. costs (sb...