算一算。

有“绿色水库”、“地球之肺”之称的生态系统是（   ）

    Now Ann is in the street. She wants to go to the post office. But she doesn't know how to go there.

Ann: Excuse me. Is there a post office near here?

The man: Yes, there is.

Ann: How can I get to the post office?

The man: Go straight and then turn right at the traffic lights. You can see the post office. It is near the library.

Ann: Is it on the left or on the right of the library?

The man: It is on the left.

Ann: Thanks very much.

The man: You are welcome.