英语怎么说：我参加了丰富的社会活动。

I have rich experiences in social activities. 这个是强调经历的丰富.

I have participated in various social activities.
或
I have participated in diversified social activities.
这两句强调社会活动的多样性.

或者把两个意思合起来:

I have rich experiences in various social activities.

i join the rich social practice.

i paticipate a lot of social activities

I have taken part in a variety of activities.

I have taken part in a variety of social activities