A: My teacher told me that are home to many and plants. Did you know that? B: Of course. Plants are very useful for. For example, trees clean the air and produce . A: Oh, you like geography as me! Let’s see who knows more B: OK. Let me start. The oceans are home to millions of animals. They absorb, transfer and move the sun’s A: Interesting! The Arctic and Antarctic are places B: I know. The sea is covered in there. What about ? A: Rivers collect water and take it to the . And river plants absorb and clean the water so we can drink it B: I see. Our planet is !