Chia dạng đúng của động từ

1. Tracy (not see)... her friends for 2 years
2. When... (you / begin)... studying English?
3. I don't think I (be)... able to pass the exams
4. If you want (lose)... weight, you should do a lot of exercise
5. He is interested in (find)... a new job
6. Ba's home village (lie)... near the foot of a mountain and by a river