Respuestas
If we stop throwing rubbish in the street, air pollution will decrease.
-If you start using electric cars more, you will help solving the problem with cars' fumes.
-If people get informed about contamination's consecuences, they will care a bit more.
-Dumpsites will be twice their actual size if we don't start recycling.
-I will start going to college by bike if you do so.
-If we stop deforestation now, we will be making a big change in world's future.
-Many species will disappear if that company doesn't stop throwing garbage in the river.
-If famous people start caring for nature, common people will do so too.
-If people like you keep on using paper for no reason, forest will be in big danger.
-If he doesn't fix his car's pollutions problem, they (will not/won't) let him drive any more.