六 阅读书信，选择正确的答案。
Dear Mary,
How are you? I have some cool news to share. Today we had the Tiangong Class. It was really amazing!
The teachers were the taikonauts on China’s Tiangong space station. I learnt a lot about space science in class.
In space, things are very different from those on Earth. The taikonauts can’t walk. They “fly” around()! Water is also different in space. The taikonauts drink water by “eating” water balls. They put a ping-pong ball in the water, and guess what? The ball didn’t float! It just stayed in the water.
I can’t wait for the next Tiangong Class. I will tell you more next time.
Love,
Peter
（）1. What is this letter about?
A. Peter’s school. B. China’s space station. C. The Tiangong Class.
（）2. Where were the teachers of the Tiangong Class?
A. In Peter’s school. B. In the science museum. C. On the space station.
（）3. Where was the ping-pong ball in the Tiangong Class?

1. C 2. C 3. B

七 你能整理好下面的“知识图”吗？ 试一试吧！
What do we know about Earth and its neighbours?
Ways to explore space
taikonaut/astronaut rover

Mars
☑ soil
☑ sunrise
☑ sunset
☒ alien
Is there soil on Mars? Yes, there is.
Are there any aliens on Mars? No, there aren't.
We learn about Mars, and ways to explore space.

telescope；spaceship