One possible version:
In order protect our environment,an activity can be organized by the Young League and Student's Union of your school during the weekend.
All the students in the senior grades can take active part in it.Some students may clean the playground,water the young trees and flowers,and remove weeds.Some students may collect waste paper,old books,empty cans and old toys.You can have them sorted and sent them to the recycling center.
The activity is really instructive,from which you all would realize how important protecting the environment is.
