`1.` Our volunteering in communities makes a difference

`=>` thì hiện tại đơn

`=>` S + Vs/es + O

`2.` I like to take part in volunteer work because I think it is very useful and meaningful to society

`=>` to take part in sth: tham gia cái gì đó

`=>` because + S + C + ,,,,

`3.` We should help the homeless, the elderly and abandoned children

`=>` S  + should + V + O

`4.` I have been a volunteer for five years ⇒ thì hiện tại hoàn thành

`=>` Dấu hiệu: for

`=>` S + have/has + Vpp + O + for + khoảng thời gian

`5.` Last week my class volunteered to clean the streets

`=>` thì quá khứ đơn ⇒ Dấu hiệu: last week

`=>` S + V2/ed + O

`6.` I felt more confident after participating in volunteer work

`=>` thì quá khứ đơn

`=>` S + V2/ed + O

`7.` My brother has ever donated blood three times before

`=>` thì quá khứ đơn

`=>` S + V2/ed + O

`8.` Every year we collect old books and clothes to help the poor children in the mountainous areas

`=>` thì hiện tại đơn

`=>` S + Vs/es + O

1. Our volunteering in communities makes a difference.

2. I like to part in volunteer work because I think it is very useful and meaningful to society.

3. We should help the homeless, the elderly and abandoned children.

4. I have been a volunteer for five years.

5. Last week my class volunteered to clean the streets.

6. I felt more confident after participating in volunteer work.

7. My brother has ever donated blood three times before.

8. Every year we collect old books and clothes to help the poor children in the mountainous areas.