Viết lại câu cho phù hợp

Câu 26: People speak English all over the world.

-> English

Câu 27: Many rivers and lakes are poisoned. Factories produce waste and pour it into rivers and lakes.

-> Because

Câu 28: They provided food then they cleaned up the debris.

-> After

Câu 29: We have learnt English for four years.

-> We started

Câu 30: Students are more aware of protecting the environment. Teachers teach environmental issues at school.