keep a running account of 把教授在课堂讲的内容都记下来
　　keep a straight face 忍住不笑出来
　　keep an eye on 留意
　　keep an eye on sth 密切注意
　　keep body and soul together 继续活下去
　　keep company 陪伴
　　keep in touch with 联系
　　keep it to yourself 保密
　　keep it under your hat 保密
　　keep my fingers crossed 交叉手指，乞求某事成功
　　keep one's head 镇定
　　keep one's head above water 活下去
　　keep one's nose to the grand stone 孜孜工作
　　keep one's shirt on 不动手打架
　　keep pace with 保持同步
　　keep punching 继续努力
　　keep sb at arm's length 疏远；保持距离
　　keep track of 登记；记录
　　keep track of one's attendance 留意某人的出勤
　　keep track of time 记住时间
　　kick downstairs 被撤职
　　kick off 开始干某事
　　kick sb upstairs 明升暗降
　　kick the bucket 死了
　　kidding around 老开玩笑
　　kill time 消磨时间
　　kill time 消磨时间
　　kill two birds with one stone 一石二鸟
　　killing one 笑死某人；痛死某人
　　knock it off 别再讲下去了
　　Knock on wood. 说话禁忌，赶紧讨个吉利。
　　knock one flat 把某人打倒在地
　　knock oneself out 精疲力尽
　　knock their eyes out 漂亮得使他们目瞪口呆
　　know one's onions 精通某事
　　know one's way around 熟悉道路
　　know-it-all 似乎样样事都知道的人