count
The manager needs an assistant so that he can ___to take care of problems in his absence. A count on B count in C count up D count out
楼上那位老师一定是笔误了，应该选A啦。 因为这里只有A count on sb有"依赖、依靠"的意思，其他几种搭配均没有此意，另外一个与count on sb常考的词组是rely on sb,也是搭配的意思。
答：M={y│y>0},N={y│y>=0},M∩N={y│y>0}详情>>
