Here are the present perfect forms of the verbs in brackets:

1. There **have been** (be) a lot of changes in Vietnam since the 1990s.
2. She **has not had** (not/have) any fun for a long time.
3. You **have not done** (not/do) your project yet, I suppose.
4. My son **has studied** (study) English since he was a young man.
5. My brother **has not had** (not have) his car repaired since I left him.
6. This is the first time that I ever **have eaten** (eat) this kind of food.
7. My friends **have been drinking** (drink) since it started to rain.