III. Put the verbs into the correct tenses or forms.
1. Linh is my close friend. We (know)........... each other for five years.
2. Lan says she enjoys (collect)............. pens but she won’t continue her hobby next year.
3. We (clean)............... up the dirty streets in our area last Sunday.
4. My mother (cook)......... in the kitchen at the moment. She likes cooking very much.
5. A lot of things (do)………… to protect our environment.
6. English (speak)……………. all over the world.
7. Your teeth should (brush)……………….. twice a day.