Drop in顺便拜访 如Do drop in if you happen to be passing!如果你碰巧经过时进来坐坐。Drop out 离开, 退出如He says he has dropped out, and won't attend college any more.他说他退了学, 以后也不会去上大学了。Pick out取出, 去掉如The child refuses to eat this fruit without first picking out the stones. 不把果核取出来, 那个小孩就不会吃这水果。pick up 安排接取 题中是说coo...
