高炉煤气中可燃气体有（）。 A.CO、H2、CH4； B.CO、H2、N2； C.C

命题“若a＞b，则a﹣1＞b﹣2”的逆否命题为（    ）

索引属于 ______。

A．模式

B．内模式

C．外模式

D．概念模式

阅读理解。

     Bullies are a big problem in schools. Every week, many children are afraid to go to school. They are

afraid they will be played jokes on by a bully. One study found that 52% of children reported being bullied

at least once a week. Sixty percent say that they know someone who could harm them. One student was

always being joked because he was short. He didn't like to go to school because he had to face the bullies.

     Some children choose not to go to school at all so they can avoid the bullies. When they miss school,

students fall behind their classmates. A new program is helping put an end to this problem. The program

is teaching kids how to deal with bullies. This is helping more children feel safe in school.

     One school principal is working to end this negative behavior. Last year, he decided to let students know

bullying is not allowed there. Students are now encouraged to report bullies and stand up for themselves.

Those found to be bullies face harsh penalties (处罚). Students at his school participate in a program called

"Be Bold". In this program, students work together to prevent violence. They do skits and go into classrooms

to talk about the problem. They give other students strategies (策略) on how to deal with bullies.

     The principal says that the school has changed since he has addressed the bullying problem. But there

are other steps parents can take to help their children with this problem. First, students and their parents

should know the school's rules about bullying and what they should do if it happens. Second, children should

be taught to stand up for themselves. They should try to resolve issues by talking them out. If the problem

continues, parents and children should record each incident. Children should tell someone if they are being

joked. Many children keep bullying a secret.

     Parents should look for warning signs of bullying. These can include cuts and bruises (瘀伤), worrying,

wanting to stay home from school, or a sudden drop in grades.

1. What's the topic of the First paragraph? [ ]

A. Bullies are a big problem in schools.

B. Some students didn't go to school because they had to face the bullies.

C. Most students are being bullied at least once a week.

D. The bullies in the campus are out of control.

2. The bullies in school can mainly be solved by _____. [     ]

A. the principal's address

B. the parents' measures

C. the students' talking them out

D. harsh penalties

3. Which of the following statements is NOT true according to the passage? [ ]

A. A bully is a person who is habitually cruel or overbearing, especially to Smaller or weaker people.

B. The best way to avoid the bullies is to miss school.

C. The school has taken some active measures to avoid the behavior of bully.

D. It's not only the responsibility of school to fight with bullies.

被称为我国“南大门”的是[ ]

A、海南岛　　

B、珠江三角洲　　

C、港澳地区　　

D、台湾岛

光通量的单位对应表示符号是（）。

A.1m

B.cd

C.1x

D.nt