If the polar ice cap melted, huge landmasses will be under the water

If the polar ice caped melted, huge landmasses will be under the water

If the polar ice caps melted, huge landmasses will under the water

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

If the air in the city is pollutes, it can cause people’s respiratory problems

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

If the air in the city was polluted, it can cause people’s respiratory problems

If the air in the city is polluted, it could cause people’s respiratory problems

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

If smog was frequently formed in the city, it’ll cause difficulty in breathing, headache and even lung cancer

If smog is frequently formed in the city, it’d cause difficulty in breathing, headache and even lung cancer

If smog were frequently formed in the city, it’ll cause difficulty in breathing, headache and even lung cancer

If carbon monoxide concentrated in great amounts, it’ll be harmful

If carbon monoxide concentrate in great amounts, it’ll be harmful

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

If carbon monoxide concentrating in great amounts, it’ll be harmful

The climate’ll change if more trees were cut down for hardwood

The climate’ll change if more trees is cut down for hardwood

The climate’ll change if more trees are cutted down for hardwood

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

If we do control the pollution soon, it will be too late

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

If we do not control the pollution soon, it would be too late

If we do not control the pollution soon, it will too late

If we don’t protected the frontier, we will suffer from many natural disasters

If we don’t protects the frontier, we will suffer from many natural disasters

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

If we don’t protect the frontier, we will be suffer from many natural disasters

If they had enough money, they could buy a new ca

If they have enough money, they could buy a new ca

If they had enough money, they can buy a new ca

If they had enough money, they buy a new ca

If people don’t stop dumping waste into rivers, the pollution would increase.

If people don’t stop dumping waste into rivers, the pollution will increases.

If people don’t stops dumping waste into rivers, the pollution will increase.

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