英语：最常用英语单词：key

　1.key:

　　① 钥匙(n.)

　　I can`t find the key to the door.

　　② 答案(n.)

　　a test with key 附答案的测试题

　　③ (打字机、钢琴等的) 键(n.)

　　④ 关键、要害(n.)

　　Diet and exercise are the key to good health.

　　2.kill (熟义：杀) vt.消磨

　　They played cards to kill time.