Teacher: Yesterday, we learned some important geographical facts. I hope you all still remember them. I'm going to test you now by asking a few questions. First, what's the highest mountain in the world.
Boy2: Qomolangma！It's higher than any other mountain in the world.
Teacher: That's right. And who can tell me what the Sahara is？
Girl 1: The Sahara is the biggest desert in the world.
Teacher: Very good. And which is the deepest salt lake in the world?
Girl2: The Caspian Sea is the deepest of all the salt lakes.
Teacher: You're all so smart！ Now, for the last question, which is the longest river in the world?
Boy 1: I know！The Nile is the longest river in the world.
Boy2: And the Amazon is the second longest river in the world.
Teacher: It seems that you know the answers to all my questions. Good job！
Mike: Hi, I'm Mike. I'm from the United States.
Boy: Welcome to our class, Mike. We're happy to meet you.
Mike: Can you tell me a bit more about China？
Girl: Sure！ Did you know that China is one of the oldest countries in the world? It's over 5,000 years old.
Mike: Yes, I did. It's much older than my country-in fact, the United States is one of the youngest countries in the world. It's not even 300 years old.
Boy: And China has the biggest population, too. It's a lot bigger than the population of the United States.
Mike: But China is about the same size as the US, right?
Girl: Yes, and it's the biggest country in Asia. We also have some famous rivers. The Yangtze River is the longest river in Asia. It's about 6,300 kilometers long.
Mike: Wow！ I didn't know that. I thought the Yellow River was longer.
Boy: No, the Yellow River is 5,464 kilometers long. But both rivers are very important to China.
Teacher: Do you have any questions about baby pandas?
Boyl: Are they much smaller than an adult panda?
Teacher: Yes. When they're born, they only weigh about 0.l to 0.2 kilos.
Boyl: Wow, that’s small！I know an adult panda weighs many times more than a baby.
Teacher: That's right. And the adult pandas weigh around 100 kilos.
Boy2: What about the size of a baby panda? How small is it?
Teacher: At birth, it's only around 15 cm（centimetre [?sent?mi:t?(r)]） long, but an adult panda is around150 cm long. Girll: Is a baby panda also black and white?
Teacher: No, you would never guess! A baby panda is pink and it cannot see. It also doesn’t have any teeth.
Girll: How long can pandas live?
Teacher: They can live up to 20 to 30 years.