IV. Listen to the dialogue and fill in the blanks. 

Mr. Liu: Yesterday, we learned some facts about the world. I’m going to test you now. What’s the biggest ocean in the world?

  Susan: The Pacific Ocean. No ocean in the world is as big as it.

Mr. Liu: That’s right. And who can tell me what the Sahara is?

    Tom: The Sahara is the biggest desert in the world.

Mr. Liu: Very good. Which is the second longest river in the world?

    Kate: I know. The Amazon. And the Nile is the longest river in the world.

Mr. Liu: You’re so smart! Which is the deepest salt lake in the world?

   John: The Caspian Sea. It’s deeper than anyother salt lake.

Mr. Liu: How deep is the Caspian Sea?

   Mary: It’s about 1,025 meters deep.

Mr. Liu: Good job!