Identify the unclear pronoun references in the following paragraph. Where necessary, rewrite the sentences so that all pronoun references are clear: —

Do you know the importance of trees? They are our best friends. Our existence on earth will be at stake without it. We inhale oxygen which trees producE- Again, we exhale carbon dioxide which it absorb. Besides, we get food from trees and firewood to cook it. But some irresponsible people cut down trees indiscriminately. It should be brought to light. Furthermore, one should take keen interest to plant more trees so that we can live comfortably on earth.