Question

One step too far

Scientists have been trying to figure out how to alter the genes of humans for many years now, and it looks like they've finally cracked (破解) the code. But while this may seem like a great step forward in science, some also believe that it's one step back when it comes to ethics.

In August, a group of scientists from the US and South Korea worked together to successfully edit a human embryo and remove a genetic mutation (突变) that would have led to heart disease, reported The Guardian.

This was achieved with the help of CRISPR, a gene-editing tool that allows scientists to “cut and paste” human DNA.

Although this was the first example of an embryo's genes being changed successfully, the benefits of gene editing have already been tested in living patients.

In 2015, a five-month-old girl from the UK was saved after doctors used edited cells to fight off her cancer. As of today, she's alive and well.

And in the US last year, scientists managed to remove HIV cells from several patients by editing the genes inside their bodies.

Some people hope that in the future, diseases or birth detects could simply be “edited out”. However, others believe this could lead to so-called designer babies, giving parents the option to choose everything from eye color to intelligence.

“You could find wealthy parents buying the latest ‘upgrades’ for their children, leading to even greater inequality than we already live with,” Marcy Darnovsky, director of the San Francisco Center for Genetics, told BBC News.

In spite of these ethical concerns, experts say it’s not possible to create the “perfect” human being. Despite the progress scientists have made, we don’t understand human genes enough to give all unborn child great brainpower or amazing singing abilities.

“Right now, we know nothing about genetic enhancement,” Hank Greely, a director of sciences at Stanford University, US, told The New York Times. “We’re never going to be able to say, honestly, ‘This embryo looks like it would score high on the two-part SAT.’”

So it looks like if we want good exam results, or to impress people with our piano skills, we’ll have to stick with the old fashioned method of plain hard work — at least for now.

1.The underlined word “alter” in Paragraph 1 probably means ______.

A.record

B.change

C.remove

D.increase

2.Why do some people consider human gene editing a step backwards？ ______

A.They don't think it is an effective way to light diseases.

B.They are concerned that it could lead to genetic mutations.

C.They think it could lead to designer babies and increased inequality.

D.They worry that it could make parents abandon children with birth defects.

3.What was the first successful example of human embryo gene editing？ ______

A.A genetic mutation related to heart disease was removed by scientists

B.A newborn baby with cancer was saved by edited cells.

C.HIV cells were removed from patients’ bodies.

D.Some birth defects were simply edited out.

4.What can we conclude from the text？ ______

A.Gene editing is regarded as the perfect way to treat birth defects.

B.There is still a long way to go to fully understand human genes.

C.Gene editing could help enhance human intelligence in the near future.

D.Scientists are pessimistic about the future of gene editing.

Answer

1.B

2.C

3.A

4.B

【解析】

本文是一篇说明文。文章介绍了科学家们在研究人类基因上取得的一些成果以及仍然面临的问题。

1.词义猜测题。根据划线词后的and it looks like they've finally cracked (破解) the code.可知，看起来他们终于破解了密码，这说明科学家们一直在研究如何改变人类的基因，由此可知划线词词义为“改变”。故B项正确。

2.细节理解题。根据第七段中的However，others believe this could lead to so-called designer babies，giving parents the option to choose everything from eye color to intelligence.可知，然而，另一些人认为，这可能会导致所谓的“设计师婴儿”，让父母可以选择从眼睛颜色到智力等一切东西；再根据第八段中的You could find wealthy parents buying the latest ‘upgrades’ for their children, leading to even greater inequality than we already live with 可知，你可能会发现富有的父母为他们的孩子购买最新的基因升级产品，导致比我们已经所拥有的更严重的不平等，由此可知，有些人认为人类基因编辑是一种倒退是他们认为这可能会导致“设计师婴儿”和加剧不平等性。故C项正确。

3.细节理解题。根据第二段In August, a group of scientists from the US and South Korea worked together to successfully edit a human embryo and remove a genetic mutation (突变) that would have led to heart disease, reported The Guardian.可知，据英国《卫报》报道，今年8月，一组来自美国和韩国的科学家共同努力，成功编辑了一个人类胚胎，并移除了一个可能导致心脏病的基因突变，由此可知，人类胚胎基因编辑的第一个成功例子是一个与心脏病有关的基因突变被科学家们移除了。故A项正确。

4.推理判断题。根据倒数第三段中的Despite the progress scientists have made, we don’t understand human genes enough to give all unborn child great brainpower or amazing singing abilities.可知，尽管科学家们已经取得了进步，但我们对人类基因的了解还不足以让所有未出生的孩子拥有强大的智力或惊人的歌唱能力；再根据最后一段So it looks like if we want good exam results, or to impress people with our piano skills, we’ll have to stick with the old fashioned method of plain hard work — at least for now.可知，所以看来，如果我们想取得好的考试成绩，或者想用我们的钢琴技巧给人们留下深刻的印象，我们就必须坚持用传统的方法，至少现在是这样，由此可知，要完全了解人类基因还有很长的路要走，故B项正确。