If you do not pollute, you have a better world.

Water Pollution

If you close the key of water, you conserve water.

If you had wash the car with tray, you could save more water.

Visual Pollution

If not put commercials, helps reduce pollution.

If he had not graffiti wall, could reduce pollution.

Land Pollution

If she strip trash, it contaminates.

If he had picked up the trash, could reduce pollution.

Air Pollution

If they take public transportation, they do not pollute.

If they had used bike, they could pollute much less.