Here are the completed sentences using "both," "either," "neither," or "of" where necessary:

1. **My** parents are from Egypt.
2. I asked two people the way to the station, but **neither** of them could help me.
3. There were two windows in the room. It was so warm that I opened **both** of them.
4. I tried twice to phone Ali, but **both** times he was out.
5. Tom’s parents **are** English. His father is Italian and his mother is French.
6. I've got two sisters and a brother. My brother is working, but **neither** of my sisters are still at school.
7. Mona and Soha play tennis regularly, but **neither** of them can play well.
8. I saw an accident this morning. One car drove into the back of another. Fortunately, **neither** driver was injured, but **both** cars were badly damaged.
9. I was invited to two parties last week, but I could not go to **either** of them.
10. To get to the town center, you can go along the footpath by the river or you can go along the road. You can go **either** way.
11. Mona and I couldn’t get into the house because **neither** of us had a key.