1. She was working as a volunteer at the local centre for community development.

2. Cleaning up the park once a week or volunteering at an orphanage.

3. She needs to fill in the form and send it in.
bài 3:
 

-ed: excited (hào hứng)

-ing: interesting (thú vị)

-ful: successful (thành công), useful (hữu ích)

-less: endless (vô tận)
bài 4:
1. was working
2. was visiting