hand over hand/fist中的over是什么意思啊?

hand over hand/fist中的over是什么意思啊? over hand 是什么意思? hand in glove,hand over fist,hand to mouth,man and boy,man a hand over take over 区别 hand over意思 hand over造句 hand over head hand over the get the upper hand over hand in 和 hand over 的一道单选题 Please hand me the book over there. gain the upper hand over意思