1. People think that students should wear uniforms when they are at school.
-> It is believed that students should wear uniforms when they are at school.

2. "Why don't you visit the Royal Citadel, Hoa?" Hoang said
-> Hoang suggested that Hoa visit the Royal Citadel.

3. They has built a new school in my neighborhood.
-> A new school has been built in my neighborhood.

4. "I'm going on business tomorrow." said Ann.
-> Ann said that she was going on business the next day.