12．Your smart phone can do a lot of things．It can call people．It connects to the Internet．It enables you to play fun games．But there is a dark side-it might also spread diseases．
This may be hard to believe，but scientists reached this conclusion after they tested eight random cell phones from an office in Chicago．All the tested phones showed high numbers of bacteria，with about 2，700to 4，200 units on each phone．In drinking water，the healthy limit is less than 1unit per 100ml （毫升） of water．
Although computers，keys and pens all carry bacteria，our smart phones get far dirtier．They touch a lot of things，including our hands and the inside of our pocket or purse．We take them almost everywhere：the bus，the subway and who hasn't played smart phone games while sitting on the toilet？
What's even worse is that after the phone returns from its dirty trip，it then spends most of its time cozying up to our faces．You don't think about how often you touch your phone to your face，do you？Our noses，mouths and ears are all warm and rich in grease （油脂），an environment that bacteria really like．
Compared to traditional keyboard，touch screens spread bacteria more easily to hands．An expert in Australia warned that playing with iPads and iPhones at Apple stores is a health risk．
There is one simple and reliable way you can reduce the bacteria on your phone's surface：wash your hands regularly．So how do you keep your smart phone clean？Alcohol is effective when used to kill bacteria from the back and side of your phone．
29．What might be the disadvantage of smart phones？A
A．It might be a potential risk of diseases．
B．It can be used to make immediate talks．
C．It can be connected with the Internet．
D．It can serve as a game-playing machine．
30．Which ottle of water may be safe to drink？A
A．A 350ml bottle of water checked with 3 units of bacteria．
B．A 500ml bottle of water checked with 50 units of bacteria．
C．A 650ml bottle of water checked with 10 units of bacteria．
D．A 1000ml bottle of water checked with 15 units of bacteria．
31．Which is true according to the passage？B
A．Our keys carry more bacteria than smart phones．
B．Smart phone users risk being exposed to bacteria．
C．There's no way to reduce the bacteria on smart phones．
D．Experts warned not to touch iPhones in Apple stores．
32．What can be the best title for the passage？C
A．A New Problem of Smart Phones
B．Take Care of Your Smart Phones
C．Smart Phones-A New Health Risk
D．How to Keep Smart Phones Clean．
分析 本文屬于說明文閱讀，作者通過這篇文章主要向我們描述了手機(jī)上帶有太多的細(xì)菌，導(dǎo)致我們會出現(xiàn)很多的健康方面的問題．
解答 29．A；細(xì)節(jié)理解題．根據(jù)文中"But there is a dark side-it might also spread diseases．"（但有一個陰暗面-它也可能傳播疾�。芍悄苁謾C(jī)的缺點(diǎn)是有傳播疾病的風(fēng)險，故選A．
30．A；細(xì)節(jié)理解題．根據(jù)文中"In drinking water，the healthy limit is less than 1 unit per 100 ml （毫升） of water．"（在飲用水中，每100毫升（毫）的水，其健康限小于1單位），可知A項(xiàng)350毫升水中有三個單位的細(xì)菌，符合題意，故選A．
31．B；細(xì)節(jié)理解題．根據(jù)文中"Although computers，keys and pens all carry bacteria，our smart phones get far dirtier"（雖然電腦、鑰匙和筆都攜帶細(xì)菌，但我們的智能手機(jī)卻變得更臟了），可知智能手機(jī)用戶面臨細(xì)菌感染的風(fēng)險，故選B．
32．C；主旨大意題．通讀全文可知，作者通過這篇文章主要向我們描述了手機(jī)上帶有太多的細(xì)菌，導(dǎo)致我們會出現(xiàn)很多的健康方面的問題，所以說智能手機(jī)成為一種新的健康風(fēng)險，故選C．
點(diǎn)評 本文考察學(xué)生的細(xì)節(jié)理解能力以及細(xì)心程度，只要抓住文章的關(guān)鍵詞，采用尋讀的方法查找細(xì)節(jié)，就能找到正確答案．
