She has been learning English for six years now.

Here are the completed sentences for PART C:

1. She has been learning English for six years now.
2. We have been working on this puzzle for one hour.
3. When I entered the room, I saw that the baby was sleeping face.
4. Before I could stop, she had torn my application already.
5. During my last summer holidays, my parents sent me to Australia.
6. A large number of spiders live in our environment.
7. Don't disturb! I am cleaning the hall.
8. There is something wrong in this place. I have called the police already.
9. I will be watering these plants while you are gone.
10. He met many interesting people during his stay in Australia last year.
11. Our friends play an important role in our lives.