`1` If people don't stop dumping waste into rivers , pollution will increase

`2` If the polar ice caps melt, huge landmasses will be under water

`3` If the air in the city is polluted , it can cause people's respiratory problems

`4` If smog is frequently formed in the city , it will cause difficulty in breathing, headache and even lung cancer

`5` If carbon monoxide concentrates in great amounts , it will be harmful

`6` The climate will change if more trees are cut down for hardwood

`7` If we don't control pollution soon , it will be too late

`8` If we don't protect the frontier forests, we will suffer from many natural disasters

Giải thích

`->` Cấu trúc câu đk loại `1` : If + mệnh đề thì HTĐ , will/can/shall/... + V-inf

`->` Dùng để nói về một sự việc có thể xảy ra ở hiện tại hoặc tương lai nếu có một điều kiện nào đó

`1)` If people don’t stop dumping waste into rivers, the pollution will increase.

`2)` If the polar ice caps melted, huge landmasses will be under the water

`3)` If the air in the city is polluted, it can cause people’s respiratory problems

`4)` If smog is frequently formed in the city, it’ll cause difficulty in breathing, headache and even lung cancer

`5)` If carbon monoxide concentrates in great amounts, it’ll be harmful

`6)` The climate’ll change if more trees are cut down for hardwood

`7)` If we do not control the pollution soon, it will be too late

`8)` If we don’t protect the frontier, we will suffer from many natural disasters