Question

    Gene therapy (基因治疗) is a revolutionary new technique for treating people with health problems. Up until very recently, the most commonly available methods for treating patients were either through drugs or operations. Gene therapy provides a third option for treatment by transforming or replacing cells with new genetic materials and instructions. Scientists can be very precise in the kinds of changes they make in patients.

Gene therapy works by using a delivery system, such as a virus, to enter a patient's body. Once inside the body, the virus combines with a host cell and delivers the new DNA. The proteins then begin to repair the affected cells. New techniques have focused on removing cells from the patients and transforming them outside the body before reintroducing them to the patients.

The two types of gene therapy are called somatic and germline. Somatic therapy refers to changing or replacing a body cell. In this case, the treatment is restricted to the patient only. This will not affect the patient's future children because the patient's germ (生殖) cells are unaffected. In germline therapy, the patient germ cells are treated, which may affect the patient's future generation.This is highly controversial (有争议的) because it is not clear exactly how this might affect them and further generations. For this reason, many countries have passed laws that prohibit this kind of treatment.

Despite the promise of gene therapy, there are still many barriers that need to be overcome before it comes into widespread use. One of the issues is that the use of viruses to deliver DNA may actually cause unexpected problems in patients if the virus grows and attacks the body. Another problem is the nature of many diseases is very complex and spread throughout multiple genes. The use of gene therapy to change a single gene in the body would probably not be sufficient as a cure. Finally, the costs of gene therapy are high. Some gene therapy procedures may cost over$1 million to undertake and require specialized doctors and equipment.

1.What does the underlined word ''them'' in paragraph 2 refer to?

A.Techniques. B.Cells. C.Patients. D.Proteins.

2.What can we learn about gene therapy?

A.Gene therapy has been put into practice widely.

B.The cells of patients are developed in healthy people.

C.Viruses entering the body can mix with host cells and form new DNA.

D.Both somatic and germline therapy have side effects on later generations.

3.What's the last paragraph mainly about?

A.The disadvantages of gene therapy.

B.The promising future of gene therapy.

C.The high costs of treatment procedures.

D.The issues related to viruses and complex genes.

4.What can be a suitable title for the text?

A.Why Gene Therapy Procedures Are Extremely Expensive

B.Gene Therapy: A Dangerous New After-operation Treatment

C.Gene Therapy: A Contemporary Progressive Treating Method

D.Scientists Are Accurate in Performing the Categories of Surgery

Answer

1.B

2.C

3.A

4.C

【解析】

这是一篇说明文。文章主要介绍了当代一种新的治疗法——基因治疗，以及它的治疗原理，人们对这种治疗的态度和可能存在的弊端。

1.词义猜测题。根据划线部分所在句子New techniques have focused on removing cells from the patients and transforming them outside the body before reintroducing them to the patients.可知，新技术着眼于从患者体内去除细胞并在将他们重新引入患者体内之前让them体外转化。结合句意可推测划线部分指代的是“细胞”。B. Cells. (细胞)符合以上说法，故选B项。

2.细节理解题。根据第二段的Once inside the body, the virus combines with a host cell and delivers the new DNA.可知，一旦进入体内，该病毒就会与宿主细胞结合并输送新的DNA。C. Viruses entering the body can mix with host cells and form new DNA. (病毒进入人体后会和宿主细胞形成新的DNA)符合以上说法，故选C项。

3.主旨大意题。根据最后一段的主要内容，尤其是第一句Despite the promise of gene therapy, there are still many barriers that need to be overcome before it comes into widespread use. (尽管基因疗法有前途，但在广泛使用之前仍需要克服许多障碍)可知，最后一段主要讲述了基因治疗的弊端。A. The disadvantages of gene therapy. (基因治疗的弊端)符合以上说法，故选A项。

4.主旨大意题。根据文章的主要内容，尤其第一段的Gene therapy(基因治疗)is a revolutionary new technique for treating people with health problems.和Gene therapy provides a third option for treatment by transforming or replacing cells with new genetic materials and instructions.(基因治疗是用来治疗有健康问题的人的一个革命性技术。基因治疗提供了第三种方法，即利用新的遗传物质和指令改造或替换细胞)可知，本文主要给这介绍一种革命性的治疗方式——基因治疗。C. Gene Therapy: A Contemporary Progressive Treating Method (基因治疗——一种现代的渐进治疗法)可以作为本文标题，故选C项。