Recent research from the Pew Internet Project suggests that 90% of Americans aged from 12 to 17 use the Internet, and 51% of those teens use social networks. However, there are many possible problems with social networking sites and the teenagers who use them.

Apart from the social advantages, social networking sites can be used to record school research, develop artistic talents and experiment with other forms of subject creation. They provide a way to communicate with others who share the same interests and to get helpful advice on ongoing projects.
Along with these advantages come some dangers. For example, most social networking sites are open to all, especially MySpace, which is the most popular social network among teens in America. It means that they could be put in unpleasant and frightening situations.
A greater danger is that teens may become objects of the people with secret purposes. The secrecy of some social networking sites makes it easy for dangerous people to find young teens and invite them into dangerous conversations. It’s easy for them to pretend as teens and draw children into dangerous real-world communication as well. Then further hurt might be on its way.
Another danger is identity stealing, which can happen when teens share too much information about their names, dates of birth and locations.
Therefore, it’s very important to make sure teens are safe when they use social networks.
Many of the same rules that work for online chat work for these sites:
※Don’t use your real name.
※ Don’t give out personal information to people you don’t know. A last name and a town
are enough for a bad guy to find where you are.
※ Don’t believe that people are who they say to be.
※ Immediately end any communication that makes you uncomfortable and report it to a
parent.
Only if you are sure of your safety, can you enjoy the fun brought by social networking. Besides, trying to deal with all problems on your own can lead to terrible results. Remember, asking your parents or school officials for help doesn’t mean you are unable to do anything but wiser than many others.                                             
【小题1】How many dangers of using social networks are mentioned in the passage?

根据短文内容，完成下面的句子，每空一词。（每小题2分，共10分）

     Do you like drinking Coke? As a symbol of American culture, Coca-Cola is liked by many people, especially young people around the world．But from now on, perhaps it will be difficult for students in the US to get it in school. A new agreement (协议) will stop almost all sales of high-sugar fizzy (起泡的) drinks in American schools.

     The agreement allows only juice, milk and water to be sold in primary schools and middle schools. It will help 35 million young people choose healthy drinks.

      Childhood obesity (肥胖) has become a big problem in America. A report shows that obesity has risen so fast in teenagers in the past 25 years. The main reason is that kids eat too much junk food and drink too much Coke.

     The UK has already used similar ways to fight obesity. A recent study shows that people in the UK are much healthier than those in the US. However, it's better late than never. Now American schools are trying to lead students to healthier lives.

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1.Coca-Cola is __________ by many __________ people around the world.

2.From now on, perhaps it won’t be __________ for students in the US to __________ Coke in school.

3. According to the agreement, only juice, milk and _______ are allowed to be sold in American _______.

4.A report __________ that teenager obesity has risen so __________ in the past 25 years.

5.People in the __________ are much __________ than those in the US.