Mai is so young, but she always gives an excellent performance

1. Mai is so young, but she always gives an excellent performance.
Although Mai ______________________________________________.
2. What is the distance between Hai Duong and Ha Noi?
How far _________________________________________________?
3. Riding a bicycle here is dangerous because this lane is for walking only.
You should not ______________________________________________________.
4. My brother usually went fishing when he was a child.
My brother used to __________________________________________________.