Listen and read.
President: Hi, welcome to our science club. Our topic today is planet Earth. Our guest is Mr An, an earth scientist.
Mr An: Hi everybody. Pleased to meet you. I'm looking forward to answering your questions about our planet.
Lan: Mr An, where's Earth in the Solar System?
Mr An: There are eight planets in the Solar System, and Earth is the third from the Sun, after Mercury and Venus. It's also the fifth largest in our system.
Nick: Is it also called the Blue Planet?
Mr An: Right From the outer space it looks blue because water covers more than 70 per cent of it.
Lan: Is it the only planet that has liquid water?
Mr An: Exactly Without it, there wouldn't be living things, like humans, or the flora and fauna of your habitat.
Nick: How about the role of air, light, and heat? How do they affect Earth?
Mr An: Well, water bodies and landforms which are main areas on Earth, together with air, light, and heat, provide essential habitats for plants and animals.
Nick: It's fascinating to observe and study these habitats.
Mr An: Yes. However, they are being destroyed by pollution. We should all help out to preserve them.