Here are the completed sentences for the exercise:

1. "Where should we find information about traditional craft villages?"
→ They didn't **know** where to find information about traditional craft villages.

2. Minh returns to his hometown every year to celebrate Tet with his family.
→ Minh **comes** back to his hometown every year to celebrate Tet with his family.

3. The new technique is less complicated than the traditional way.
→ The new technique is **more** simple than the traditional way.

4. When is the new air conditioner delivered to our house?
→ **When** does the new air conditioner get delivered to our house?

5. This homemade sauce is passed down from generation to generation in my house.
→ This homemade sauce is **handed** down from generation to generation in my house.

6. Jonathan plans to look around Melbourne and enjoy its cuisine this Sunday.
→ Jonathan is **going** to look around Melbourne and enjoy its cuisine this Sunday.

7. It’s obligatory not to drop litter around the tourist attractions in Singapore.
→ You **must** not drop litter around the tourist attractions in Singapore.

8. "Some tourists are joining a free class in making pottery right now."
→ The tour guide **said** some tourists are joining a free class in making pottery right now.

9. The electrical wires broke down after the thunderstorm, so they had to call an electrician.
→ The electrical wires broke down after the thunderstorm, **because** they had to call an electrician.

10. The community helpers come and take care of the orphans every weekend.
→ They **look** after the orphans every weekend.

Let me know if you need any further assistance!