1. Turn left at the traffic light.
 * We use "at" with specific points like traffic lights, corners, etc.
2. Go past the street.
 * "Past" means moving beyond something.
3. Excuse me. Is there a post office near here?
 * "Here" refers to the current location.
4. Let's watch TV.
 * "Watch" is the correct verb to use in this context.
5. The town has many motorbikes. It's very noisy.
 * A town with many motorbikes is typically noisy.
6. The buildings are historic. They were built 150 years ago.
 * "Historic" means old and important.
7. Hoa's new school is bigger than her old school.
 * We use the comparative form "bigger" to compare two things.
8. The streets are narrow.
 * "Narrow" means not wide.
9. You must be late for school.
 * "Must" expresses a strong obligation or necessity.
10. The Mekong is the longest river in Vietnam.
 * We use the superlative form "longest" to compare more than two things.