K

Keep an eye on 留神；注意 (来源：英语博客 http://space.englishcn.com)

keep company 陪伴

keep the ball rolling 不中断

keep a cool head 保持头脑冷静

keep one's head above water 不欠债

keep one's word 信守诺言

keep one's powder dry 保持火药干燥；有备无患

keep the pot boiling 维持生活

Keep your eyes wide open before marriage and half shut afterwards. 婚前要睁大眼睛；婚后要半闭眼睛

Keep your mouth shut and ears open. 多听少讲

kill the fatted calf 热情款待

Kill the goose that lays the golden eggs. 杀鸡取蛋；竭泽而渔

Kill two birds with one stone. 一石二鸟；一举两得

king of the castle 山大王 King Stork 残暴君王

King's English 标准英语

Kith and kin 亲戚朋友

know the ropes 懂得窍门

Knowledge comes from diligence. 知识源于勤奋

Knowledge makes humble; ignorance makes proud. 知识使人谦虚，无知使人骄傲

Knowledge is power. 知识就是力量。

Knowledge is a treasure, practice is the key to it. 知识是一座宝库，时间是库门的钥匙。