阅读材料，回答问题。 材料一：欧洲把合众国的建立视为明证：启蒙时代的许多思想都是

Jack’s friend Tony had recently gotten a tattoo (纹身), and Jack was so impressed by Tony’s bravery and his tattoo that he decided to get one too. Why do a lot of young people in North America get tattoos today Peer pressure, media influence, and personal expression are some of the common reasons.
The desire to be part of a group, to be accepted by one’s friends or peers, can have a great influence on what a person does. Sometimes, wearing a tattoo can be a sign that you belong to a certain group. Gangs often use special clothes and tattoos to identify their particular group. For example, in one gang all the members may wear green army jackets and have large "Xs" tattooed on their arms. It is not only gangs that have this type of special "uniform". Young people often belong to a certain group of friends. Some of these groups wear only brand-name clothes. Others wear tattoos. When a person’s friends are all doing something, such as getting a tattoo, that person is more likely to do the same thing, and get a tattoo too.
The media is another big influence behind the popularity of tattoos in North America. A wide variety of media images show tattoos. Tattoos can be seen on people appearing in commercials selling expensive cars. Famous sports heroes with tattoos are shown in magazines. Fashion models are often seen in magazines and on TV wearing designer clothes that show their bodies tattooed with detailed and colorful patterns. These media images link tattoos to ideas of wealth, success, and status. As a result, many people decide to get a tattoo for its fashion and status value.
It is not always the influence of other people or the media that results in a person getting a tattoo. Many people decide to wear tattoos in order to express their artistic nature, their beliefs, or their feelings -- in other words, to show their individuality. A musician in a rock band may get a tattoo of a guitar on the arm. Some environmentalists may tattoo pictures of endangered animals on their shoulders. Lovers may tattoo each others’ names over their hearts. A tattoo can be a public sign to show what is important in a person’s life.

Which of the following groups of people are seen wearing tattoos in the media

A. Sports Stars.
B. Car sellers.
C. Fashion designers.
D. Movie stars.

假设你是李华，最近国内一家英文报纸正在讨论北京动物园是否应迁出市区。以下是你所在班级讨论的情况。请你给该报写一封信，反映讨论结果。

　　注意：1．词数100字左右，信的开头已为你写好。

　　2．可根据内容要点适当增加细节，以使行文连贯。

　　3．参考词汇：郊区-suburb

哪些物质燃烧不能用水灭火？

储运氢气最安全可靠的办法是瓶装。

某工程1年建成并投产，寿命期为10年，每年净收益2万元，按10%折现率计算，恰好能在寿命期内把初始投资全部回收，则该项目的初始投资为（）万元。

A．20

B．18.42

C．12.29

D．10