Question

【題目】 Scientists say they have used the gene-editing tool CRISPR to repair a person’s eyesight for the first time. The CRISPR tool makes it possible to change DNA to add needed genes or take some away if they lead to problems.

A patient recently had the procedure done for an inherited form of blindness. The operation took place at Oregon Health and Science University in Portland. “We literally have the potential to treat people who are essentially blind and make them see,” said Charles Albright. He is chief scientific officer at Editas Medicine in Cambridge, Massachusetts. Editas is one of the companies developing the treatment. Albright added, “We think it could open up a whole new set of medicines to go in and change your DNA.”

The people taking part in the study have a genetic condition that keeps the body from making a protein needed to turn light into signals to the brain, which leads to sight.

Scientists have found it difficult to treat the condition with usual gene therapy. So, they are aiming to edit or remove the mutation（突變）by making two cuts on either side of it. The hope is that the ends of DNA will reconnect and make the gene work as it should. Through a tube the width of a human hair, doctors put three drops of fluid containing the gene editing machinery just under the retina（視網(wǎng)膜）, which is the lining at the back of the eye that contains the light-sensing cells. Doctors believe they need to fix one-tenth to one-third of the cells to repair vision. In animal tests, scientists were able to correct half of the cells with the treatment, Albright said.

Some independent experts were hopeful about the new study. Dr. Kiran Musunuru is a gene-editing expert at the University of Pennsylvania. He said the treatment seems likely to work, based on tests in mice and monkeys. The gene editing tool stays in the eye and does not travel to other parts of the body. So, “If something goes wrong, the chance of harm is very small.” Musunuru said. “It makes for a good first step for doing gene editing in the body.”

【1】Who can most possibly benefit from this new treatment?

A.Patients who are essentially color-blinded.

B.Patients who turn blind due to accidents or diseases.

C.Patients who are born with no ability to see.

D.Patients who lose their vision at a young age.

【2】Which is Paragraph 4 mainly about?

A.The result of the treatment.

B.The theory of the treatment.

C.The difficulty of the treatment.

D.The disadvantage of traditional treatment.

【3】What is likely to be discussed after the last paragraph?

A.The function of the gene-editing tool.

B.The limitation of the gene-editing tool.

C.The effect of the treatment on animals.

D.The research of the treatment on humans.

Answer 1

【答案】

【1】C

【2】B

【3】D

【解析】

這是一篇說明文。講述了科學家發(fā)現(xiàn)了一種叫作CRISPR的基因編輯工具，可以通過改變DNA來治療眼睛近視等疾病，這種工具的效果還在實驗證實中。

【1】

細節(jié)理解題。根據(jù)第一段“The CRISPR tool makes it possible to change DNA to add needed genes or take some away if they lead to problems. ”可知，這種工具是通過DNA的添加和去除來治療，所以治療的是先天疾病，且第二段中“A patient recently had the procedure done for an inherited form of blindness.”提到這個被治療的病人的眼盲是遺傳的，故選C。

【2】

主旨大意題。根據(jù)“Scientists have found it difficult to treat the condition with usual gene therapy. So, they are aiming to edit or remove the mutation（突變）by making two cuts on either side of it.”可知，科學家們發(fā)現(xiàn)普通的理論行不通，所以他們研究出了新的理論（在突變基因的一邊剪開），后文是在講該理論的作用機制和效果，所以第四段主要是講該治療的理論，故選B。

【3】

推理判斷題。根據(jù)“He said the treatment seems likely to work, based on tests in mice and monkeys.”可知，最后一段提到的實驗進程是基于老鼠和猴子身上的實驗，所以接下來要講的是在人身上的實驗，故選D。