Here are the completed sentences with the appropriate articles filled in:

1. **The** Vietnamese are known to be polite, hospitable, and sensitive.
2. In **the** countryside, parents often arrange their children’s marriages.
3. “Ao dai” is one of **the** most traditional costumes in Viet Nam.
4. My aunt made some spring rolls for **the** longevity party.
5. **The** Ok Om Bok Festival takes place in October.
6. **The** tradition of worshipping whales is popular in Vietnamese coastal villages.
7. It’s **a** tradition for shops to have **a** lion dance performance at their opening ceremony.
8. Holding **a** party to wish our grandparents longevity is one of **the** customs we practice at Tet.
9. People place **a** bamboo pole in **the** yard of **the** communal house.
10. It’s **a** custom in my family to have dinner at home on Saturdays.

For the underlining exercise, the answers are as follows:

1. What’s **the** matter? Are you all right?
2. Kate has bought a new car since **x** yesterday.
3. Some people think that **the** Moon is man-made.
4. I’m collecting money for **the** poor.
5. **x** Brian hasn’t found a job yet.
6. Can you play **the** guitar?
7. Don’t forget to turn off **the** television.
8. There’s a knife in **the** second drawer.
9. **The** art museum is in **the** city center.
10. Many Asians go to **the** Buddhist temples to pray for good luck.