杨梅是大家喜欢吃的水果，它粒大饱满，酸甜味美，也可酿制杨梅酒．请回答：

据统计，我国每年约有1．6万名中小学生非正常死亡，也就是说中小学生因意外伤害平均每天有40多人，差不多是一个班的学生在“消失”。上述材料说明中小学生（    ）

阅读下面的文章，完成小题。

“低头族”，你错过了什么

    ①好莱坞动画大片《机器人总动员》中，描述了公元2700年时人们的生活：那时的人类文明高度发达，但由于过度依赖智能设备，人们都变成四体不勤的大胖子，每时每刻面对的只有一个支在他们眼前的电脑屏幕。除了和屏幕对话，他们不懂得如何与其他人交流，甚至离开屏幕就几乎无法生存……他们就是传说中的“低头族”。

    ②事实上，世界各地智能手机普及之处，地铁里、公交车上、工作会议上、课堂上、餐桌上、排队时，甚至驾车时，总有很多人低着头，手里拿着手机或是平板电脑，手指在触摸屏上来回滑动，所有的注意力都集中在手中发亮的方寸屏幕上，对身边的世界漠不关心。

    ③首都师范大学心理咨询中心的一项调查显示：77%的人每天开机12小时以上， 33.55%的人24小时开机，65%的人表示“如果手机不在身边会有些焦虑”，超过九成的人离不开手机。智能手机带来的负面作用，现在已经开始显现了。

    ④发表在《验光和视觉科学》期刊上的一项研究指出，人们通过手机阅读文本信息或上网时，眼晴会比手里拿着一本书或一张报纸离得更近，这意味着，眼睛聚焦手机图文更费劲，更容易导致头痛和双眼疲劳等问题。

    ⑤长时间使用智能手机，会导致眼部结膜血管充血，甚至出现刺痛、流泪、畏光等症状。而长期低头看手机还会引起颈椎问题，半个小时到一个小时的低头就可引起颈部的疲劳，时间长久会引起椎间盘退型性病变、骨质增生，进而压迫血管和神经。此外，长期玩手机还会引起失眠、听力下降、手指肌腱炎等健康问题。

    ⑥因专注于手机而引发的各类事故早已不是新闻。研究表明，走路玩手机导致人们左右看的几率减少了20%，遭遇交通事故的几率增加了43%。美国俄亥俄州立大学的一项统计显示，因专注于手机而导致的伤害事件近年来明显上升。2007年有600名行人因看手机而受伤， 2010年这个数字增加到1500人。研究学者警告说：如果这一趋势继续发展的话，类似的伤害事件将在未来5年增长一倍。

    ⑦埋头于网络世界，带来的不仅是对身体的伤害，还有对人们精神世界的影响。2012年10月，青岛市民张先生与弟弟妹妹相约去爷爷家吃晚饭。饭桌上，老人多次想和孙子孙女说说话，但面前的孩子一个个拿着手机玩，老人受到冷落后，一怒之下摔了盘子离席。

    ⑧有媒体评论称：老人摔盘离席是现代社会生活的一个典型切片，手机引发的各种情感危机，在社会的各个角落里不断重复上演。沉醉于手机的虚拟空间，消解了社会伦理，致使人与人之间的关系变得冷漠、隔阂。“世界上最远的距离不是天涯海角，而是我站在你面前，你却在玩手机。”网上广为流传的这句话，反映了人们对人际交往中手机这个角色的复杂心态。

阅读理解

    BEIJING — China's education authority will tighten the widely criticized policy of “extra credits” for the national college entrance examination to ensure a fairer chance for all exam-takers.

    Under the policy, high school students who win awards in national Olympic competitions could get "extra credits', up to 20 points for the national college entrance exam. Students with talent in sports and students who are from ethnic groups can also benefit from this policy. The extra credits have increased these students' chances of being admitted by famous universities. Some parents were found to have helped their children fabricate(伪造)award experiences or falsify qualifications to get extra credits.

    “It has harmed education equality，” the ministry said.

    Xiong Bingqi, vice-chief of the 21st Century Education Research Institute, said the policy is designed to help students who have special talents but may be weak in academic performance to have a chance to receive higher education. It will still be needed but it is time to make the rules fairer," he said.

    The ministry said it will reduce the range of competitions whose winners can get extra credits, and limit the winners, privileges.

    The new policy will apply to students who begin high school in 2011, it said.

    Chen Lei, a mother of a 10-year-old girl, said she welcomed the ministry's policy adjustment as she does not want her daughter to become an Olympic competition geek.

    But not all the Chinese parents welcomed the new policy. “It is like a thunderbolt for me. My 13-year-old son has spent so much time studying Olympic math, and participated in so many technological competitions during vacations. It is useless now,” said Dong Wen, a 43-year-old mother.

    A student said, “Many students have changed the current study plan, and they can abandon the competition. I will be interested in learning the courses which can improve my abilities.”

    Yuan Guiren, minister of education, told China Daily that the reform is an attempt to consider the overall quality of an applicant. “But the country will not stop the national college entrance  examination as it is still the most objective way to evaluate talent in China,” he said.