Treatment for Dengue Fever

　　There is no vaccine to prevent dengue and no specific medicine to treat it, so the only defense is eradication of the mosquitoes that carry it and measures to protect people from mosquito bites.

　　But hope is offered by research being carried out at the Southwest Foundation for Biomedical Research in San Antonio, which relies on very special mice.

　　The small white animals with pink eyes are kept in a special isolated room so that they will not be exposed to any bacteria or germs that might infect them. They have been altered to be susceptible to human diseases.

　　Lead researcher Rebecca Rico-Hesse says the mice have been modified or humanized by an infusion of stem cells taken from human umbilical cords that were discarded at local hospitals. We have basically reconstituted the human immune system in these mice and it is only because they have these immune system cells that they can get infected and show symptoms of dengue fever, she said.

　　By infecting these humanized mice with strains of the dengue virus, investigators can study how the disease takes hold and what factors might cause the more serious and often deadly dengue hemorrhagic fever.

　　A recent report co-authored by Rico-Hesse and her colleague Javier Mota shows for the first time why some strains of dengue virus are more severe than others. In this report, we present results of eight different virus strains and we show that the ones that have been associated with the more severe epidemics and the ones that cause hemorrhagic fever in patients are actually of a specific genetic variant, she said.

　　Lab workers infect the mice artificially with the virus, keeping precise records of how much virus and what type of virus is used. But natural transmission of dengue by mosquitoes involves certain proteins the insects inject into the skin, something that Rico-Hesse says is missing when mice are artificially infected in the lab.

　　If you are just, you know, injecting it in with a syringe, you are missing out on all those salivary gland factors and all the things that happen during a natural infection that might either speed up the infection rate or decrease the infection rate. And we also need to know how many mosquitoes it takes to infect a humanized mouse, she said.

　　Rico-Hesse and her colleagues are breeding mosquitoes in the laboratory to test various strains of the dengue virus transmitted to the mice by mosquitoes.

　　Although effective vaccines or antiviral drugs for dengue may still be a long way off, researchers here say they are making important steps that they hope will one day minimize the suffering and death caused by the illness

　　1.Which statement is correct according to Paragraph 1

　　A.Dengue fever can be eradicated by mosquitoes.

　　B.Strong effect of certain medication can cure dengue fever.

　　C.By killing all the mosquitoes in the world, we can prevent dengue fever.

　　D.Scientists have invented a vaccine that can prevent dengue fever

　　正確答案:C

　　解析:問題問的是：根據第一段，正確的是哪一項?第一段中提到，沒有疫苗和藥物能預防或治愈登革熱，只有消滅所有攜帶病毒的蚊子才能防止被感染。由此可見，C選項正確

　　2.The special mice used in the lab test

　　A.have red eyes.

　　B.are kept in an ordinary open room.

　　C.are put in the room with lots of mosquitoes.

　　D.have been altered so that they can easily infected by human diseases

　　正確答案:D

　　解析:問題問的是：試驗中用到的特別的老鼠是怎樣的?A選項錯誤，第三段第一句提到老鼠眼睛是粉色的;B選項錯誤，第三段提到，老鼠被置于特殊的與病菌隔離的房間里，與選項中說的普通的開放的房間矛盾;C選項錯誤，文中提到老鼠體內的病菌是研究人員注射植入的，老鼠并沒有與蚊子放在一起。而 D中的easily infected正是第三段最后一句中susceptible的同義詞，意為易感染的。因此，D正確

　　3.According to the report, the virus strains that cause the more severe dengue and hemorrhagic fever are actually

　　A.of a specific genetic variant..

　　B.from a special mosquito.

　　C.invented in the lab.

　　D.killable with a specific genetic variant

　　正確答案:A

　　解析:問題問的是：能夠導致更加嚴重的登革熱和出血熱的病毒株實際上是什么?第六段最后一句中提到這兩種病毒株其實是屬于同一種基因變異體。因此選A。容易引起混淆的是D選項，其中提到了特殊變異體，只是該選項的意思是說病毒可以被病毒的特殊變異體殺死，顯然不對。注意killable，是 kill和able組成的合成詞，意為可殺死的

　　4.Which statement is true according to the passage

　　A.Lab workers inject into the mice the fever virus with a syringe .

　　B.The umbilical cords used in modifying the immune system of the mice are from live humans.

　　C.The artificial infection of virus has exactly the same effect as the natural one.

　　D.Rico-Hesse and her colleagues are raising mosquitoes as their pets.

　　正確答案:A

　　解析:問題問的是：關于短文，哪個觀點是正確的?文中第八段第一句就提到了A中的觀點，其中的it實際上就是指the virus，也就是病毒。B中說改變老鼠免疫系統式臍帶來自活人，這與原文中提到的來自醫院不要的臍帶不符，注意discard一詞意為 丟棄C中說人工植入的病毒與蚊子植入的病毒效果完全相同，而文中說的是人工植入的病毒缺乏唾液腺的因素，達不到自然植入的病毒的效果;D中說養蚊子做寵物顯然與原文中研究蚊子直接對老鼠傳播的病毒引發的登革熱的說法不符

　　5.What is the authors attitude to the future of the researchers work

　　A.Optimistic.

　　B.Pessimistic.

　　C.Objective.

　　D.Sarcastic

　　正確答案:C

　　解析:問題問的是：作者對該項研究的前景持何種態度?縱觀全文，作者始終非常客觀的敘述試驗的細節及進展情況，包括最后對前景的展望都是引用研究人員的原話。因此，他的態度應該是客觀的。C選項正確

　　Treatment for Dengue Fever

　　There is no vaccine to prevent dengue and no specific medicine to treat it, so the only defense is eradication of the mosquitoes that carry it and measures to protect people from mosquito bites.

　　But hope is offered by research being carried out at the Southwest Foundation for Biomedical Research in San Antonio, which relies on very special mice.

　　The small white animals with pink eyes are kept in a special isolated room so that they will not be exposed to any bacteria or germs that might infect them. They have been altered to be susceptible to human diseases.

　　Lead researcher Rebecca Rico-Hesse says the mice have been modified or humanized by an infusion of stem cells taken from human umbilical cords that were discarded at local hospitals. We have basically reconstituted the human immune system in these mice and it is only because they have these immune system cells that they can get infected and show symptoms of dengue fever, she said.

　　By infecting these humanized mice with strains of the dengue virus, investigators can study how the disease takes hold and what factors might cause the more serious and often deadly dengue hemorrhagic fever.

　　A recent report co-authored by Rico-Hesse and her colleague Javier Mota shows for the first time why some strains of dengue virus are more severe than others. In this report, we present results of eight different virus strains and we show that the ones that have been associated with the more severe epidemics and the ones that cause hemorrhagic fever in patients are actually of a specific genetic variant, she said.

　　Lab workers infect the mice artificially with the virus, keeping precise records of how much virus and what type of virus is used. But natural transmission of dengue by mosquitoes involves certain proteins the insects inject into the skin, something that Rico-Hesse says is missing when mice are artificially infected in the lab.

　　If you are just, you know, injecting it in with a syringe, you are missing out on all those salivary gland factors and all the things that happen during a natural infection that might either speed up the infection rate or decrease the infection rate. And we also need to know how many mosquitoes it takes to infect a humanized mouse, she said.

　　Rico-Hesse and her colleagues are breeding mosquitoes in the laboratory to test various strains of the dengue virus transmitted to the mice by mosquitoes.

　　Although effective vaccines or antiviral drugs for dengue may still be a long way off, researchers here say they are making important steps that they hope will one day minimize the suffering and death caused by the illness

　　1.Which statement is correct according to Paragraph 1

　　A.Dengue fever can be eradicated by mosquitoes.

　　B.Strong effect of certain medication can cure dengue fever.

　　C.By killing all the mosquitoes in the world, we can prevent dengue fever.

　　D.Scientists have invented a vaccine that can prevent dengue fever

　　正確答案:C

　　解析:問題問的是：根據第一段，正確的是哪一項?第一段中提到，沒有疫苗和藥物能預防或治愈登革熱，只有消滅所有攜帶病毒的蚊子才能防止被感染。由此可見，C選項正確

　　2.The special mice used in the lab test

　　A.have red eyes.

　　B.are kept in an ordinary open room.

　　C.are put in the room with lots of mosquitoes.

　　D.have been altered so that they can easily infected by human diseases

　　正確答案:D

　　解析:問題問的是：試驗中用到的特別的老鼠是怎樣的?A選項錯誤，第三段第一句提到老鼠眼睛是粉色的;B選項錯誤，第三段提到，老鼠被置于特殊的與病菌隔離的房間里，與選項中說的普通的開放的房間矛盾;C選項錯誤，文中提到老鼠體內的病菌是研究人員注射植入的，老鼠并沒有與蚊子放在一起。而 D中的easily infected正是第三段最后一句中susceptible的同義詞，意為易感染的。因此，D正確

　　3.According to the report, the virus strains that cause the more severe dengue and hemorrhagic fever are actually

　　A.of a specific genetic variant..

　　B.from a special mosquito.

　　C.invented in the lab.

　　D.killable with a specific genetic variant

　　正確答案:A

　　解析:問題問的是：能夠導致更加嚴重的登革熱和出血熱的病毒株實際上是什么?第六段最后一句中提到這兩種病毒株其實是屬于同一種基因變異體。因此選A。容易引起混淆的是D選項，其中提到了特殊變異體，只是該選項的意思是說病毒可以被病毒的特殊變異體殺死，顯然不對。注意killable，是 kill和able組成的合成詞，意為可殺死的

　　4.Which statement is true according to the passage

　　A.Lab workers inject into the mice the fever virus with a syringe .

　　B.The umbilical cords used in modifying the immune system of the mice are from live humans.

　　C.The artificial infection of virus has exactly the same effect as the natural one.

　　D.Rico-Hesse and her colleagues are raising mosquitoes as their pets.

　　正確答案:A

　　解析:問題問的是：關于短文，哪個觀點是正確的?文中第八段第一句就提到了A中的觀點，其中的it實際上就是指the virus，也就是病毒。B中說改變老鼠免疫系統式臍帶來自活人，這與原文中提到的來自醫院不要的臍帶不符，注意discard一詞意為 丟棄C中說人工植入的病毒與蚊子植入的病毒效果完全相同，而文中說的是人工植入的病毒缺乏唾液腺的因素，達不到自然植入的病毒的效果;D中說養蚊子做寵物顯然與原文中研究蚊子直接對老鼠傳播的病毒引發的登革熱的說法不符

　　5.What is the authors attitude to the future of the researchers work

　　A.Optimistic.

　　B.Pessimistic.

　　C.Objective.

　　D.Sarcastic

　　正確答案:C

　　解析:問題問的是：作者對該項研究的前景持何種態度?縱觀全文，作者始終非常客觀的敘述試驗的細節及進展情況，包括最后對前景的展望都是引用研究人員的原話。因此，他的態度應該是客觀的。C選項正確