阅读理解
The Internet plays a big part in human life.We use it for work and pleasure.We use it to learn a new language.We find advice on it.We use it to connect with family and friends.We use it to stay in touch with events we care about.The list goes on and on.
Well，that__train__has__left__the__station．But can using the Internet too much be bad for our health？It might be，researchers say.A new study finds that heavy Internet use may be connected to high blood pressure(血压)in an unlikely group：teenagers.
High blood pressure makes your heart and blood vessels(血管)work too hard.Over time，this extra pressure increases your risk of a heart attack.High blood pressure can also cause heart and kidney(肾脏)disease.It is also closely linked to a brain disease.
The Henry Ford Hospital in Detroit，Michigan did the study.335 young people from 14 to 17 years old，took part in it.134 of the teens were described as “heavy Internet users”. And researchers found that out of these 134 teens，26 had high blood pressure.
The lead researcher is Andrea Cassidy－Bushrow.She said，“Using the Internet is part of our daily life，but it shouldn’t ruin us.” Ms. Cassidy－Bushrow adds that it is important for teens to take regular breaks from their computers or smartphones and do some kind of physical activity.She also suggests that parents limit(限制)their children’s use of the Internet to two hours a day，five days a week.
【解题导语】 本文是一篇说明文。一项研究发现，青少年过度使用因特网可能会导致高血压。
1．The underlined expression “that train has left the station” in Para.2 is used to show________．
A．the Internet develops rapidly
B．no one can escape from the Internet
C．the Internet can provide whatever we want
D．there is no going back to an Internet－free life
D 解析：句意理解题。文章首句讲到现在因特网对于人类生活来说至关重要，接着列举了我们日常生活中用到因特网的方方面面。在第二段作者引用了这句that train has left the station，紧跟着又提出疑问：过度使用因特网会不会影响我们的健康？由此可知这句话在此处所要表达的意思就是：我们不能返回到没有因特网的生活了。
2．What is Para.3 mainly about?
A．Causes of high blood pressure.
B．The harm of high blood pressure.
C．The disadvantages of Internet use.
D．Ways to prevent high blood pressure.
B 解析：段落大意题。根据文章第三段的内容可知，本段讲的是高血压的种种危害。
3．Andrea Cassidy－Bushrow would agree that ________．
A．teenagers shouldn’t use the Internet
B．the Internet will ruin human life in the future
C．smartphones are more harmful than computers
D．regular breaks are necessary when using the Internet
D 解析：推理判断题。根据文章最后一段中的Ms.Cassidy－Bushrow adds that it is important for teens to take regular breaks from their computers or smartphones...可知，Andrea Cassidy－Bushrow认为上网时隔一段时间就休息一下是很有必要的。
4．What can be used as the best title of the passage?
A．Heavy Internet Users Are Mostly Teenagers
B．How to Prevent Teenagers from the Internet
C．Too Much Internet Use May Be Bad for Teenagers
D．Every Coin Has Two Sides—So Does the Internet
C 解析：标题归纳题。文章主要讲的是一项研究发现青少年过度使用因特网可能会导致高血压，由此可知C项作为文章标题最佳。
