Here are the completed sentences:

2. Because Lan used to live in London, she knows western culture well.
Lan knows western culture well because she used to live in London.


3. Children are not allowed to drink any type of alcohol.
Children mustn't drink any type of alcohol.


4. While he was watching television, we came into the room.
He was watching television when we came into the room.


5. It is advisable for students to take a bow on seeing a teacher from a distance.
Students should take a bow when they see a teacher from a distance.


6. Mrs. Madison was tired, but she tried to finish all the housework.
Despite being tired, Mrs. Madison tried to finish all the housework.


7. What is the length of time of the Iditarod Trail Sled Dog Race?
How long is the Iditarod Trail Sled Dog Race?


8. We won’t go to visit Huong Pagoda if it is too crowded.
Unless it is not too crowded, we won’t go to visit Huong Pagoda.



Let me know if you need further clarification or assistance!