题干
Dear Jack,
Can you believe I'm in a school of 2030 now? The school is like a beautiful garden. The wall of our classroom is colorful. Our school life is interesting.
In the morning, we have three classes. We study on the Internet. We use the e-books. The teachers are all robots. They are in different rooms and they can answer any questions. Our robot music teacher plays the guitar very well. In the afternoon, we take a plane to the Mars to have two classes. I make friends with aliens(外星人). They are friendly and know us well. After class, we play soccer with them. Then we go back to the earth. Don't you think the life in this school is very interesting?
Mary
The school life in 2030 | ____ | |
What to do | In the morning | They have three classes. They study on the ____ |
The robot teachers can answer any questions. | ||
In the afternoon | They go to the Mars ____ to have class. | |
Mary makes friends with ____ aliens. | ||
After class | They play soccer with aliens. | |
Then they ____ to the earth. | ||
表示氧原子， 
表示氢原子．根据此图，试分别从物质组成、分子构成、物质变化的角度各说出一种观点． 