1.Students are more aware of protecting the environment. Teachers teach environmental issues at school.

⇒if teachers teach environmental issues at school, students will be more aware of protecting the environment

→câu điều kiện loại 1:CT If +thì hiện tại đơn, will + V-inf

2.People speak English all over the world. 

⇒english is spoken all over the world

→ S + be+V3/Ved (+ by O)

3.Many rivers and lakes are poisoned.Factories produce waste and pour it into rivers and lakes.

⇒ because factories produce waste and pour it into rivers and lakes many rivers and lakes are poisoned

→ta có mệnh đề ' factories produce waste and pour it into rivers and lakes'là mệnh đề chỉ nguyên nhân nên ta để sau because(lưu ý nếu because đặt ở trước thì cách 1 mệnh đề phải có dấu phẩy)

4.They provided food then cleared up the debris.

⇒after they had provided food, they cleared up the debris

→sau after QKHT một hành động sảy ra trước, QKĐ cho hành động xảy ra sau

~Chúc bạn học tốt~

@TommyThrisk

=>

1. If teachers teach environmental issues at school, students will be more aware of protecting the environment.

-> câu đk loại 1: If S Vs/es, S will V

2. English is spoken all over the world.

-> bị động HTĐ is/am/are V3/ed

3. Because factories produce waste and pour it into rivers and lakes, many rivers and lakes are poisoned.

-> because S V: bởi vì

4. After they had provided food, they cleared up the debris.

-> after QKHT, QKĐ