knock out
A: 敲击
B: 逃跑
C: 点头
D: 击倒，使无效
A: 敲击
B: 逃跑
C: 点头
D: 击倒，使无效
D
举一反三
- knock out（基因敲除）
- He had three of his teeth _______ out in the fight. A: knocking B: knock C: knocked D: be knocking
- knock at/on 敲knock into 撞到某人身上knock down 撞倒knock out of 把…敲出knock over 撞倒knock off 停止工作，休息1) The boxer soon knocked his opponent ________ __.2) The office stuff knocks _________ ___ at six every day.3) Try knocking __________ ___ the window and see if there is anyone indoors.4) He was so absorbed in his book that he knocked __________ _____ the car parked there.
- Suddenly he heard someone（）gently on the window. A: knock B: knocking C: knocked D: to knock
- A: Listen! There__________ someone __________ at the door.B: It must be your sister. A: is; knocking B: is; knock C: are; knocking D: are; knock
内容
- 0
Knock a total of ______ times. Each knock ______. A: one B: two C: three D: four E: five
- 1
I heard someone _______ loudly at the door while I was listening to the radio. A: knock B: knocking C: to knock D: knocked
- 2
基因剔除（knock out）的方法主要用证明（） A: 基因的调控 B: 基因的结构 C: 基因的表达 D: RNA的特殊区域 E: 基因的功能
- 3
中国大学MOOC: 使用榔头敲击时，应使榔头的端面始终垂直于所敲击的工件。
- 4
在需要与同学或者老师面对面交谈时,下列做法正确的是( ) A: 眼神飘忽,左顾右盼 B: 撑手敲击桌面 C: 哈欠连天 D: 面带微笑,时不时微微点头