毒品车的编码是（）。

下边这幅漫画说明

A．中国已是贸易强国

B．要提高自主创新能力，提高对外开放水平

C．要多引进先进技术，增强中国创造的力量

D．中国已融入世界，与世界各国取长补短

如图所示，空间某区域中有一匀强磁场，磁感应强度方向垂直纸面向里，磁场上、下边界分别位于水平面2、4处．在竖直面内有一矩形金属线圈，线圈上下边的距离很短，磁场上下边界之间的距离大于水平面1、2之间的距离．线圈下边位于水平面1处，由静止释放．若线圈下边刚通过水平面1、2、3（位于磁场中）和4时，线圈的加速度大小分别为a₁、a₂、a₃和a₄，且下落过程始终做加速运动，则（　　）

A．a₁=a₃＞a₂＞a₄

B．a₁＜a₂＜a₃＜a₄

C．a₁＞a₂＞a₃＞a₄

D．a₁＞a₃＞a₄＞a₂

阅读理解。

     Many students want to find friends on the Internet as a way of practising their language skills and learning

more about new cultures. Traditional pen pals were the main source (起源) of such contacts, and students

could write to each other. With the Internet, finding friends has become much easier, and such relationships

are called keypals.

     However, careful thinking should be given when finding friends on the Internet:

     First, search the Internet for famous services. Look for reviews of such sites to learn more about other

students' experiences. Don't join a service until you have done your research.

     Second, check to see if you can use a false name, rather than your real name, to protect your identity.

Never give personal information to anyone, including your home address, phone number and birthday.

     Third, stop contacting others if you feel uncomfortable with the topics of conversation. Tell your teachers,

parents, or even the local government if you find that you are in danger.

     And finally, try to use the language you are studying in the classroom in your communications with others.

Ask proper questions that will also help you learn about other cultures. Remember that one's personal

experience might be just that: To understand a whole culture, you have to talk to many people, but this will get

you started. Good luck.

1. If you are not comfortable with the topics,you should _____. [ ]

A. talk about something else with others

B. stop communicating with others

C. ask your teachers or parents for advice

D. tell him to stop talking about the topics

2. The underlined word"identity" probably means _____. [ ]

A. name

B. address

C. family

D. personal information

3. It can be seen from the passage that _____. [ ]

A. the writer is worried about the studens searching the Intemet

B. to know more about a culture,you need to communicate with many people

C. in order to protect yourself,you'd better tell lies on the Internet

D. many people will talk to you if you ask questions about their culture

4. Which of the following is TRUE?[ ]

A. Many students want to make friends on the Internet to practe their English.

B. It's easy to make friends with experienced students on the Internet.

C. Exchange your phone number with your keypals to keep in touch with them.

D. Ask your teachers or parents for help when you find that you are in danger

5. Which of the following would be the best title for the passage? [ ]

A. How to Find Friends on the Internet

B. How to go on the Internet

C. How to Practise Language Skills

D. How to Contact People

( )是P2DR模型的核心。