阅读理解。
Students should dress well at school. This is because schools are places where students study. Students
shouldn't be dressed fashionably or strangely. That is thought of as impolite behavior at school. So many
schools have their own school uniforms. In general, the price is cheaper than that of common clothes in
markets. The colors and styles between boys' and girls' are different. And each uniform has the school name
where the student studies. Many students think they look very nice.
However, some schools also allow students to choose other clothes they like. But those who wear other
clothes must obey the school rules about clothing at school. The following are rules from Zhongshan Middle
school.
* Clothing must cover shoulders and backs.
* No halter tops (三角背心) are allowed.
* Skirts must be long enough to cover girl's knees. Skirt straps (裙带) must be as wide as three fingers.
* Shorts must be at least as long as where your finger tips are when your arms are straight by your side.
* Sleeveless (无袖) shirts are only OK for boys.
1. Why can't students wear fashionable clothing at school?
A. Because fashionable clothing looks beautiful.
B. Because fashionable clothing is strange.
C. Because fashionable clothing has a different color from school uniforms.
D. Because students will be thought of impolite.
2. When we see a student's school uniform, we may know ______.
A. where the school is
B. where the student lives
C. what the teacher's name is
D. which school the student studies at
3. According to the passage, we can know that ______.
A. some schools allow students to wear common clothes
B. school uniforms are more expensive than common clothes in markets
C. both boys and girls can wear halter tops at Zhongshan Middle School
D. at Zhongshan Middle School, girls are required to wear sleeveless shirts
4. Which picture shows good manners at Zhongshan Middle School?
A B C D
5. The passage mainly talks about ______.
A. sleeveless shirts
B. rules of dressing in schools
C. fashionable clothes
D. different school uniforms
CO↑+ CO2↑+3H2O.某实验小组为检验草酸分解产物中是否有CO，设计了如下图所示的实验装置。回答下列有关问题：
