attend 参加会议或仪式

attend

参加会议或仪式

（如：婚礼、葬礼、典礼等；上学、上课、听报告等）

take part in

参加会议或群众性活动

（如：运动会、体育等）

join

参加某个组织或团体（如：参军、入党、入团）

join (s.b) in (doing) s.th

参加活动或比赛

eg:

He attended school at the age of 6.

He often takes part in sports.

His wish is to join the army after graduation.

Tom, we'll go (out) for a picnic this weekend. Will you join us?

All the neighbours joined the sad family in finding the lost boy.