（2013·宁波）若右图中猫的头部位置保持不变，把镜子沿MN截成两半，并分别向两侧平移一段距离，则猫的头部通过左、右两半面镜子（    ）

阅读下列短文, 根据短文中的信息完成文后表格, 每空一词。

      WARNING(警告): Holding a cell phone against your ear or putting it in your pocket may be bad for your health. This sentence is a warning that you’d better not put it close to you when a new phone is bought. Apple company, for example, doesn't want iPhones to come closer to you than 1.5 centimeters; Research In Motion, BlackBerry's producer, recommends 2.5 centimeters.

      If cell phone use can cause health problems, the result will be very serious. Americans spend 2.26 trillion minutes chatting on cell phones every year, which brings $109 billion for the wireless businessmen.

      Devra Davis, an epidemiologist(皮肤病专家)who has worked for the University of Pittsburgh, has published a book about mobile phone radiation(辐射)"Disconnect." Davis studies how often brain cancer happens during different age groups. As a result of mobile phone radiation, she finds that a big increase(增长)in brain cancer in the 20-to-29 age group and a drop for the older people.

      Children are more easily hurt by radiation than grown-ups, Ms. Davis and other scientists point out. But no studies have yet been finished on cell phone radiation and children, she says.

      Henry Lai, a research professor, began lab radiation studies in 1980 and found that mice exposed to(暴露在) radiofrequency（电波频率）radiation had destroyed DNA in their brains.

      Ms. Davis recommends using wired earphones（有线耳机）or the phone's speaker. Children should send text messages rather than call, she said, and pregnant women should keep phones away from their bodies.

有学者这样描述我国古代的君臣关系：在宋以前大臣“坐而论道”，从宋太祖以后“站而论道”,到了明清只能“跪奏笔录”，这反映的问题是（   ）