同学你好，该知识点来自沪江网校《低起点直达CATTI二级（笔译+口译）【全额奖学金班】》的课程，想要更系统的学习，欢迎进入课程学习。不仅可以和更多的同学一起学习，而且还有老师、助教随时的学习指导和知识点解答哦。

同学好~
这两组短语各自都有很多含义哦，具体区别如下：
knock off
1.knock off (sth) to stop working and go somewhere else 停止（工作）; 下班
  There was no one in the office because they'd all knocked off for lunch.
  办公室里没人，因为他们都停下工作吃午饭去了。
2.  knock sth ↔ off to reduce the price of something by a particular amount〔从价钱中〕减去〔一定数额〕
  I'll knock off ￡10. 我愿意降 10 英镑。
  knock sth off sth
  Travel agents are knocking ￡50 and sometimes ￡100 off the price of holidays.
  旅行代理人会把度假报价降 50 英镑，有时 100 英镑。
3.knock sth ↔ off to reduce a total by a particular amount〔从总量中〕去掉，减少〔一定数量〕
  knock sth off sth
  Moving house will knock an hour off Ray's journey to work. 搬家将使雷的上班路程缩短一小时。
4. knock sth ↔ off to produce something quickly and easily〔快速轻松地〕做出某物，做完某事
  Roland makes a lot of money knocking off copies of famous paintings.罗伦靠快速仿制名画赚大钱。
5. knock sb ↔ off to murder someone 杀害某人
6. knock sth ↔ off [BrE] to steal something 偷某物，偷窃某物

get off
1. to leave a place, or to help someone to leave a place（使）离开，（使）动身
  We'll try and get off straight after lunch. 我们尽量吃过午饭就出发。
  get off sth
  Get off my land! 从我的土地上走开！
  get sb off
  I'll phone you as soon as I've got the children off to school. 我把孩子们打发上学后马上打电话给你。
2.get off (sth) to finish work and leave the place where you work at the end of the day 下班
  I usually get off at six o'clock. 我一般六点钟下班。
  What time do you get off work ? 你什么时候下班？
3. get sth off to send a letter or package by post 邮寄某物，寄出某物
  I'll have to get this letter off by tonight.我得在今晚前把这封信寄出去。
  I'll get the forms off to you today.今天我会把表格寄给你。
4.  get sth off to remove a piece of clothing 脱下，脱掉
  Why don't you get those wet clothes off?  你干吗不把湿衣服脱下来？
5.if someone gets off, they are not punished for doing something wrong, or they receive only a small punishment 没有受到惩罚; 被从轻处罚
  In the end he got off because there wasn't enough evidence against him.
最后他因为证据不足没有受到惩罚。
  If you're lucky, you'll get off with a fine. 你运气好的话，罚点钱就可以了。
6. HELP SB NOT BE PUNISHED 帮助某人免受处罚, get sb off to help someone avoid being punished for a crime
  使某人免受处罚:
  Her lawyers were confident that they could get her off.
  她的律师有信心让她无罪。
7. get (sb) off to go to sleep, or to help a child go to sleep 睡觉; 哄（某人）睡觉
  I went to bed but couldn't get off to sleep . 我上了床，但是睡不着。
  It took us ages to get the baby off. 我们好久才把宝宝哄睡着了。
8. get off to a good / bad etc start, to start in a particular way 有好/不好等的开端
  The day had got off to a bad start. 这天一早就有坏事发生。
9. 停止谈论某事, get off sth to stop talking about a subject 不再谈论某事
  Can we get off the subject of death, please? 我们不说死亡这个话题了好不好？
10. get off (sth / sb) [informal] used to tell someone to stop touching something or someone 不要碰（某物/某人）
  Get off me! 别碰我！
  Get off those cakes, or there'll be trouble. 别碰那些蛋糕，否则有你好看的。

希望对同学有帮助，学习进步~