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.

材料一 风能发电有着广阔的市场和前景。

风能发电是目前可再生能源中最有效的一项能源技术，它既能化解温室效应带来的气候危机，也可提供稳定的能源供应．中国风能资源仅次于美国和俄罗斯，居世界第三位．

材料二   我国冬、夏季风图

某同学分别测量了三块橡皮泥的质量和体积，并根据测量数据画出如图所示的图像，橡皮泥的密度是____ g／cm³。若另一块同种橡皮泥的体积为20 cm³，其质量是____ g。