1. take/have/play no part in...: to deliberately not take part in something, because you disagree with it or think it is wrong

备注：''take/have/play no part in...''常用于非正式的场合。

例：

They were pacifists and would take no part in the war. （他们都是和平主义者，不会参战。）

Jen would have no part in forcing Gwen out of her job. （珍不会跟他们一起逼格温辞职。）

I played no part in leaking the information to the press. （不是我把消息透露给媒体的。）

2. withdraw: to decide not to take part in a competition, race, discussion etc., which you previously agreed to take part in

例：

withdraw from

Clare had to withdraw from the race after injuring her knee. （克莱尔膝盖受伤后，不得不退赛。）

It will be very sad if Jordan withdraws from politics altogether. （如果乔丹彻底退出政坛的话很可惜。）

3. pull/drop out: to suddenly decide not to take part in something, that has already started or is about to start, especially when this causes problems

备注：''pull out''常用于非正式的场合，比''withdraw''更口语化

例：

He pulled out with an injury at the last minute.(最后一刻，他因伤退出。)

The show was canceled when the star unexpectedly pulled out. （那个明星突然说不来了，表演因此取消。）

By the end of the semester about half of the students had dropped out. （到学期末，约有一半学生退学。）

pull/drop out of

Most of the other Democratic candidates had already dropped out of the presidential race. （很多民主党候选人已经退出总统竞选。）

He threatened to pull his son out of the team. （他威胁说要让他儿子退队。）

4. opt out: to decide not to take part in an official system, especially one that has not started yet

例：

Employees who do not wish to be part of the company's healthcare program can opt out if they want to. （不想在公司交医保的员工可以不交。）

5. have nothing to do with: to not be involved in any way in something bad or illegal - use this especially when other people think that you were involved

例：

I'm sure that Tony had nothing to do with the robbery. （我敢保证托尼肯定不会去抢劫。）

Connie had nothing to do with the break-up of my marriage. （我离婚跟科尼无关。）

6. take no further part in: to stop taking part in something that you were actively involved in before

例：

She was injured and took no further part in the game. （她受伤不能再参加比赛了。）

7. armchair:

armchair traveler/fan etc: someone who talks or reads about being a traveler, or watches sport on television but does not have any real experience of doing it 

例：

Her books about her adventures give enjoyment and inspiration to armchair travelers. （她以自己的冒险经历写成的书让旅游爱好者足不出户也能好好过过瘾。）

Armchair travelers can now visit the world's most exotic countries via the Internet. （现在，有了因特网，旅游爱好者足不出户也能尽享异国风光。）

Armchair fans will have to pay extra to watch the best games live. （粉丝想在家里观看顶级赛事现场直播，需要额外付费。）

8. on the sidelines: if you stay, sit, or wait on the sidelines when something is happening, you do not take part in it, even though you may want to or should do

例：

You can't just wait on the sidelines and hope things will improve. （你不能什么都不做袖手旁观，又指望情况会好转。）

How can we sit on the sidelines when thousands of innocent civilians are being killed. （眼看无辜平民被杀，我们怎么能袖手旁观。）