13．Medical drugs sometimes cause more damage than they cure．One solution to this problem is to put the drugs inside a capsule，protecting them from the body-and the body from them-until they can be released at just the right spot．There are lots of ways to trigger （引發(fā)） this release，including changing temperature，acidity，and so on．But triggers can come with their own risks-burns，for example．Now，researchers in California have designed what could be a harmless trigger to date：shining near-infrared light （NIR，近紅外線） on the drug in the capsule．
The idea of using light to liberate the drug in the capsule isn't new．Researchers around the globe have developed polymers （聚合物） and other materials that begin to break down when they absorb either ultraviolet （UV，紫外線） or visible light．But tissues also readily absorb UV and visible light，which means the drug release can be triggered only near the skin，where the light can reach the capsule．NIR light largely passes through tissues，so researchers have tried to use it as a trigger．But few compounds （化合物） absorb NIR well and go through chemical changes．
That changed last year when Adah Almutairi，a chemist at the University of California，San Diego，reported that she and her colleagues had designed a polymer that breaks down when it absorbs NIR light．Their polymer used a commercially available NIR-absorbing group called o-nitrobenzyl （ONB）．When they catch the light，ONB groups fall off the polymer，leading to its breakdown．But ONB is only a so-so NIR absorber，and it could be poisonous to cells when it separates from the polymer．
So Almutairi and her colleagues reported creating a new material for capsules that's even better．This one consists of a long chain of compounds called cresol groups linked in a polymer．Cresol contains reactive（易反應(yīng)的） components that make it highly unstable in its polymeric form，a feature Almutairi and her colleagues use to their advantage．After polymerizing the cresols，they cap each reactive component with a light-absorbing compound called Bhc．When the Bhcs absorb NIR light，the reactive groups are exposed and break the long polymer into two short chains．Shining additional light continues this breakdown，potentially releasing any drugs in the capsule．What's more，Almutairi says，Bhc is 10times better at absorbing NIR than is ONB and is not poisonous to cells．
63．According to the passage，which of the following could be the best trigger？B
A．Temperature change．
B．NIR light．
C．Acidity change．
D．UV light．
64．Why is ONB unsatisfactory？D
A．It breaks down when it absorbs NIR light．
B．It falls off the polymer and triggers drug release．
C．It has not come onto the market up till now．
D．It is not effective enough and could be poisonous．
65．Which word can be used to complete the following process of changes？C
A．protected
B．formed
C．exposed
D．combined．
分析 本文是一篇科普文章，主要圍繞"怎樣使用膠囊，讓我們生病更加安全、而且療效好"這個(gè)主題展開(kāi)話題，解決方法之一是將藥物裝入膠囊內(nèi)，通過(guò)紅外線來(lái)引發(fā)膠囊藥物的釋放．
解答 63．B 細(xì)節(jié)推理題．根據(jù)第一段最后兩句"Now，researchers in California have designed what could be a harmless trigger to date：shining near-infrared light on the drug in the capsule．"可知，研究者設(shè)計(jì)了一種包含在藥物膠囊里的無(wú)害的觸發(fā)器，通過(guò)紅外線來(lái)引發(fā)膠囊藥物的釋放，因此最后的觸發(fā)器是NIR light，故選B．
64．D 細(xì)節(jié)理解題．根據(jù)第三段尾句"But ONB is only a so-so NIR absorber，and it could be poisonous tocells when it separates from the polymer．"可知，六氯還已烷對(duì)身體細(xì)胞沒(méi)有害，在吸收近紅外線方面，比鄰硝基要好10倍并且對(duì)細(xì)胞不會(huì)產(chǎn)生有害副作用，故選D．
65．C 細(xì)節(jié)歸納題．根據(jù)尾段關(guān)鍵詞、句"a long chain of compounds called cresol groups""Cresol contains reactive（易反應(yīng)的） componentsthat…""When…，the reactivegroups are exposed and break…""…continues thisbreakdown"可知，六氯還已烷吸收近紅外線后，易反應(yīng)性組曝光，把長(zhǎng)鏈聚合物破壞成兩個(gè)短鏈聚合物．故選C．
點(diǎn)評(píng) 解答細(xì)節(jié)理解題時(shí)，一個(gè)常用的方法就是運(yùn)用定位法，即根據(jù)題干和選項(xiàng)中的關(guān)鍵詞從原文中找到相關(guān)的句子，與選項(xiàng)進(jìn)行比較從而確定答案；推理判斷題既要求學(xué)生透過(guò)文章表面文字信息推測(cè)文章隱含意思，又要求學(xué)生對(duì)作者的態(tài)度、意圖及文章細(xì)節(jié)的發(fā)展作正確的推理判斷，力求從作者的角度去考慮，不要固守自己的看法或觀點(diǎn)．
