Here are the rewritten sentences according to your requests:

1. What is the distance between Thanh Mien and Ha Noi?
→ How far is it from Thanh Mien to Ha Noi?

2. This is our school.
→ This school is ours.

3. Tom was a poor student. However, he studied very well.
→ Although Tom was a poor student, he studied very well.

4. The distance from Ha Noi to Hai Phong city is about 100 kilometres.
→ It is about 100 kilometres from Ha Noi to Hai Phong city.

5. Although they are short, they still love playing sports.
→ In spite of being short, they still love playing sports.