Câu đk loại I:
- If everyone puts the garbage into the bins, the environmental pollution will decrease
- If more people cycle, there will be less air pollution
- If we pollute the water, we will have no fresh water to use
- If we discharge dirty water out, the environment will be polluted
- If factories do not emit toxic gases, the air will not be polluted

Câu đk loại II:
- If peole used more many plastic, the earth would be more polluted
- If I littered messy, environment would be polluted
- If we didn't grow green trees, we don't have  clean environment
- If many fishes died, the sea would be polluted
- If we didn't have awareness to environmental, our habitat would be dirty