2018年公共英语五级阅读理解模拟题（13）

　　公共英语五级阅读理解模拟题

At 18, Ashanthi DeSilva of suburban Cleveland is a living symbol of one of the great intellectual achievements of the 20th century. Born with an extremely rare and usually fatal disorder that left her without a functioning immune system (the "bubble-boy disease", named after an earlier victim who was kept alive for years in a sterile plastictent), she was treated beginning in 1990 with a revolutionary new therapy that sought to correct the defect at its very

source, in the genes of her white blood cells. It worked. Although her last gene-therapy treatment was in 1992, she is completely healthy with normal immune function, according to one of the doctors who treated her, W. French Anderson of the University of Southern California. Researchers have long dreamed of treating diseases from hemophilia to cancer by replacing mutant genes with normal ones. And the dreaming may continue for decades more.

"there will be a gene-based treatment for essentially every disease, " Anderson says, "within 50 years. "

It’ s not entirely clear why medicine has been so slow to build on Anderson’ s early success. The National Insti- tutes of Health budget office estimates it will spend $ 432 million on gene-therapy research in 2005, and there is no shortage of promising leads. The therapeutic genes are usually delivered through viruses that don’ t cause human disease. "The virus is sort of like a Trojan horse, " says Ronald Crystal of New York Presbyterian/Weill Cornell Medical College. "The cargo is the gene. "

At the University of Pennsylvania’ s Abramson Cancer Center, immunologist Carl June recently treated HIV patients with a gene intended to help their cells resist the infection. At Cornell University. researchers are pursuing gene-based therapies for Parkinson’ s disease and a rare hereditary disorder that destroys children" s brain cells. At Stanford University and the Children’ s Hospital of Philadelphia, researchers are trying to figure out bow to help pa- tients with hemophilia who today must inject themselves with expensive clotting drugs for life. Animal experiments have shown great promise.

But somehow, things get lost in the translation from laboratory to patient. In human trials of the hemophilia treatment, patients show a response at first, but it fades over time. And the field has still not recovered from the set- back it suffered in 1999, when Jesse Gelsinger, an 18-year-old with a rare metabolic disorder, died after receiving an experimental gene therapy at the University of Pennsylvania. Some experts worry that the field will be tarnished fur- ther if the next people to benefit are not patients but athletes seeking an edge. This summer, researchers at the Salk Institute in San Diego said they had created a "marathon mouse" by implanting a gene that enhances running ability;already, officials at the World Anti-Doping Agency are preparing to test athletes for signs of "gene doping". But the principle is the same, whether you’ re trying to help a healthy runner run faster or allow a muscular-dystrophy patient to walk. "Everybody recognizes that gene therapy is a very good idea, " says Crystal. "And eventually it’ s going to work. ""

56. The case of Ashanthi Desilva is mentioned in the text to

A. show the promise of gene-therapy

B. give an example of modern treatment for fatal diseases

C. introduce the achievement of Anderson and his team

D. explain how gene-based treatment works

57. Anderson’ s early success has ____

A. greatly speeded the development of medicine

B. brought no immediate progress in the research of gene-therapy

C. promised a cure to every disease

D. made him a national hero

58. Which of the following is true according to the text?

A. Ashanthi needs to receive gene-therapy treatment constantly.

B. Despite the huge funding, gene researches have shown few promises.

C. Therapeutic genes are carded by harmless viruses.

D. Gene-doping is encouraged by world agencies to help athletes get better scores.

59. The word "tarnish" (line 4, paragraph 4) most probably means __

A. affect

B. warn

C. trouble

D. stain

6O. From the text we can see that the author seems

A. optimistic

B. pessimistic

C. troubled

D. uncertain

　　答案及解析

56.A【解析】文章第一句话对用基因疗法治疗Ashanthi所患罕见疾病的成功给予了很高的评价，并在第一段末指出医生们对基因疗法寄予了极高的期望。因此正确答案为A。

57.B【解析】文章第二段一开头就说：…It S not entirely clear whv medi—cine has been SO slow to build on Anderson’S early Success.”从时间上来看，Anderson采用基因疗法的成功尝试已经是l990年的事情了，两相对照，可见他的成功没有让医学加速发展。因此正确答案为B。

58.c【解析】文章第二段对于基因治疗的方式的解释是用于治疗的基因通过“viruses that don’t cause human disease”进入体内，就好像“特洛伊木马”一样，由此可见，这些病毒是无害的。因此正确答案为C。

59.D【解析】第四段提到基因疗法遭受的一起挫折——一个病人因接受基因疗法而死亡;接着讲专家担心运动员利用基因在比赛中作弊会进一步tarnish这一领域，从上下文逻辑推理，应该是“有损，玷污”这一类的意思，因此正确答案为D。

60.A【解析】作者的态度从文章第一句话和最后一句话就可以明显判断出来。第一句话说基因疗法是20世纪的伟大成就之一，最后一句话说“Everybody recogllizes that gene therapy is a very good idea”，由此可见作者对基因疗法持积极乐观的态度。因此正确答案为A。