Question

Conventional wisdom says that hardship can make us old before our time. In fact, a new study suggests that violence not only leaves long-term scars on children?s bodies, but also changes their DNA, causing changes that are equal to seven to ten years of premature aging.

Scientists measured this by studying the ends of children?s chromosomes(染色体), called telomeres, says Idan Shalev, lead author of a study published in Molecular Psychiatry.

Telomeres are special DNA sequences which prevent the DNA in chromosomes from separating. They get shorter each time a cell divides, until a cell cannot divide any more and dies.

Several factors have been found to shorten telomeres, including smoking, radiation and psychological stresses such as being treated badly when young and taking care of a chronically ill person.

In this study, researchers examined whether exposure to violence could make children’s telomeres shorten faster than normal. They interviewed the mothers of 236 children at ages 5, 7 and 10, asking whether the youngsters had been exposed to domestic violence between the mother and her partner; physical maltreatment by an adult; or bullying. Researchers measured the children’s telomeres—in cells obtained by swabbing the insides of their cheeks—at ages 5 and 10.

Telomeres shortened faster in kids exposed to two or more types of violence, says Shalev. Unless that pattern changes, the study suggests, these kids could be expected to develop diseases of aging, such as heart attacks or memory loss, seven to 10 years earlier than their peers.

Shalev says there is hope for these kids. His study found that, in rare cases, telomeres can lengthen. Better nutrition, exercise and stress reduction are three things that may be able to lengthen telomeres, he says.

The study confirms a small ­but­ growing number of studies suggesting that early childhood adversity imprints itself in our chromosomes, says Charles Nelson, a professor of pediatrics and neuroscience at Harvard Medical School.

1.The new study found that ________.

A. hardship can change a child?s aging

B. violence leaves scars on a child?s mind

C. violence can speed up a child?s aging

D. hardship has a long ­term effect on a child?s mind

2.According to the text, telomeres ________.

A. are at the ends of people?s chromosomes

B. can help prevent DNA from separating

C. can make a cell die quickly

D. become shorter before they die

3.Which of the following is TRUE according to the text?

A. Violence can cause quick cell division in children?s body.

B. Researchers measured the children?s telomeres from their legs in the study.

C. Being treated badly will make a child?s telomeres shorten faster.

D. Children who have shorter telomeres may have a heart attack earlier.

4.What is the best title for the text?

A. Violence Aging Children?s DNA

B. Children?s Changing DNA Patterns

C. Violence and Telomeres

D. The Function of Telomeres

Answer 1

1.C

2.B

3.D

4.A

【解析】

试题分析：文章主要叙述了一些发展中国家女孩受教育的现状以及给社会带来的不利影响，呼吁人们重视女孩的教育。

1. 细节理解题。根据文章中的第一段In fact, a new study suggests that violence not only leaves long-term scars on children?s bodies, but also changes their DNA, causing changes that are equal to seven to ten years of premature aging.研究表明，暴力不仅可以影响孩子的身体，也能改变他们的DNA,也能导致改变同期年龄的老化。

2. 细节理解题。根据文章第三段中的Telomeres are special DNA sequences which prevent the DNA in chromosomes from separating.可知端粒是DNA的序列，可以阻止染色体中的DNA分裂。根据第二段中Scientists measured this by studying the ends of children?s chromosomes(染色体), called telomeres,科学家们通过研究孩子们的染色体的末端来检测，可知A错误；根据第三段中的They get shorter each time a cell divides, until a cell cannot divide any more and dies每次一个细胞分化就会变得更短，直到细胞不能再次分化并死亡。.可知C、D错误。故选B

3. 推理判断题。根据第五段最后一句in cells obtained by swabbing the insides of their cheeks?at ages 5 and 10.细胞包含在5到10岁的脸颊里擦拭。可以推知B错误；由第六段Telomeres shortened faster in kids exposed to two or more types of violence,在孩子两种或两种以上类型的暴力中，端粒会变短的速度更快。可知C 错误；A文中未提及。由第六段the study suggests, these kids could be expected to develop diseases of aging, such as heart attacks or memory loss, seven to 10 years earlier than their peers.研究建议，这些孩子希望可以改善年龄老化的疾病，例如心脏病或者失忆，比同龄的人要早7到10年。可知选D。

4. 主旨大意题，根据全文的内容可知，文章描述了主要说明暴力会加速DNA中端粒的变短而让孩子们提前衰老，而A项则很好地概括了文章大意，故选A。

考点：科普类文章阅读。