TED Talk, Strayer explained that all this time spent with technology is making our brains tired.

　　Using an electronic device to answer emails, listen to the news and look at social media puts a lot of pressure on the front of the brain, which, Strayer explains, is important for critical(有判断力的) thinking, problem­solving and decision­making.

　　So, it is important to give the brain a rest. And being in nature, Strayer claims, helps get a tired brain away from too much technology. More than 15，000 campers from around the world attended an international camping festival in September. That is when friends and family take time off and escape to nature for several days. They take walks, climb, explore, swim, sleep, eat and play. Camping may be just what a tired brain needs.

　　Take Carl for example. He lives in West Virginia and enjoys camping. He says that staying outdoors makes him feel at ease. It also prepares him for the work he must do. Kate Somers is another example who also lives in West Virginia. She says she enjoys camping with her husband and two children. She calls it a "regenerative" experience.

　　At the University of Utah, David Strayer has studied both short­term and long­term exposure to nature. He found that spending short amounts of time in nature without technology does calm the brain and helps it to remember better. However, he found, it is the long­term contact with nature that does the most good. He and his research team found that spending three days in nature without any technology is enough time for the brain to fully relax and reset itself.

　　【解题导语】　本文是一篇说明文，作者讲述了如今长时间使用电子设备对大脑的危害，鼓励人们放下这些电子设备，去户外让大脑休息一下。

　　5．What is David Strayer's opinion?

　　A．Americans dislike outdoor activities.

　　B．Electronic equipment should be quitted.

　　C．New technologies are a double­edged sword.

　　D．Electronic equipment brings great convenience.

　　C　解析：推理判断题。依据第一段可知，David Strayer认为过多使用电子设备导致大脑疲劳，第二段中的"answer emails, listen to the news and look at social media"暗示着电子设备给我们生活带来的便利，因此科技有利有弊，选项C正确。

　　6．Why does Strayer insist we go outdoors?

　　A．To try another lifestyle.

　　B．To refresh our brain.

C．To make better decisions.