老是弄混~~~~(>-

解题思路： 如下
解题过程：
join,join in和take part in
1)加入某党派、某组织或某社会团体，用join，不可用join in。如：
①He will never forget the day when he joined the Party.
他永远也忘不了他入党的那一天。
②His brother joined the army three years ago.
他哥哥是三年前参军的。
join还可解释为“连接”。如：
①The railway joined the two cities.
铁路把两个城市连接起来了。
②The two clauses are joined by a conjunction.
两个分句由一个连词连接起来。

2)说参加某种活动用join in，如说“与其人一起做某事”，则用join sb. in sth. / doing sth. 。如：
①May I join in the game? 我可以参加这个游戏吗？
②Come and join us in the discussion. 来和我们一起讨论吧！
③We are having supper now.Would you like to join us?
我们正在吃晚饭，你也来和我们一起吃好吗？
join in多指参加小规模的活动如“球赛、游戏”等，常用于日常口语。如：
①Come along, and join in the ball game. 快，来参加球赛。
②Why didn't you join in the talk last night? 昨晚你为什么没参加座谈？

3)take part in参加(群众性活动、会议等)，往往指参加者持积极态度．起一份作用。如：
①A great number of students took part in May 4 Movement.
大批学生参加了五四运动。
②We are going to have an English evening. Do you want to take part?
我们准备举办一个英语晚会，你想参加吗？
③How many of you are going to take part?
你们多少人准备参加？
④All the students took an active part in the thorough cleaning.
所有的学生都积极参加了大扫除。

【注意】take part in是惯用词组，part前一般不用冠词，但part前有形容词修饰时，要用不定冠词。如：
Lincoln took an active part in polities and was strongly against slavery.
林肯积极参加政治活动，强烈反对奴隶制。
最终答案：略