Here are the sentences completed with the appropriate conjunctions:

2. He's a fashion designer. He wants to see the ao dai fashion show; therefore, he will attend.

3. I may go to the Do Son - Buffalo fighting Festival; I may visit the Elephant Race Festival, or I might choose another event.

4. Huong Pagoda Festival attracts a lot of Vietnamese people and is popular with foreigners too; moreover, it offers a rich cultural experience.

5. They would like to attend Giong Festival because they want to show their love for their motherland.

6. They believe they have to pray to the God. If they don't do so, the God will not bless them; otherwise, they may face difficulties.

7. Huong Pagoda Festival was expected to be crowded, but we decided to go anyway; although it might be busy, we wanted to experience it.