阅读理解。
Starting a stamp collection is easy and not very expensive. Before you start, you need to decide
what kind of stamps you want to collect. Most people collect stamps that they are interested in: a
certain country or an animal, a famous person or even a sport. Whatever you choose, you will find
that there is a world of knowledge in stamps: you will learn about people, geography, building, history
and culture.
You can collect stamps from letters, ask your friends to let you have their old stamps, or you can
buy used stamps. When you get a letter with a stamp on it, carefully cut out the stamp. Leave lots of
space around the stamp so that you will not damage it. Put the stamp in water and wait until you can
safely remove the stamp. Carefully remove the stamp off the letter. Place the wet stamp between two
clean pieces of paper. A stamp can get wrinkled(褶皱的) when it dries, so put some books on top.
1. What does the writer think of collecting stamps?
A. Hard
B. Expensive
C. Useful
D. Boring
2. What does the underlined work "damage" mean?
A. 损坏
B. 保存
C. 利用
D. 删除
3.What's the correct order when we try to get a stamp on a letter?
①Remove the stamp off the letter.
②Place the wet stamp between two pieces of paper.
③Cut out the stamp.
④Put the stamp in water.
⑤Put some books on top.
A. ①→②→⑤→③→④
B. ③→④→①→②→⑤
C. ④→①→②→⑤→③
D. ③→①→④→②→⑤
对X进行两次独立观察，其结果分别记为
2NH3(g) △H<0，得到如下数据 