in and out 进进出出；曲曲弯弯；一来一往 (介词短语作状语）

(1)进进出出 

She keeps popping in and out. 

她不停地走进走出。 

The boy chased his sister in and out among the bushes. 

那个男孩在灌木丛里跟着他姐姐追过来追过去。 

Her back was aching from having to get down in order to put things in and out of the bottom drawer. 

由于必须弯下腰来从最下面的抽屉中把东西拿进拿出, 她腰酸背痛了。 

(2)曲曲弯弯 

Lying as it does in the deep waters of the Western Pacific, Japan winds in and out like a snake from southwest to northeast, a distance of more than two thousand miles. 

日本这个国家位于西太平洋的深水地带, 像蛇一样弯弯曲曲地自西南向东北延伸, 全长两千多英里。 

over the past few months=在过去的几年中（介词短语作状语）

(over 为介词：意思在…期间）

The number of attacks on the capital had gone down over the past week

上一周对首都的袭击次数已经减少了。

Many strikes over the last few years have not ended successfully.

过去几年中有多次罢工都未获成功。