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(染色體), 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】

試題分析：文章主要敘述了一些發(fā)展中國家女孩受教育的現(xiàn)狀以及給社會帶來的不利影響，呼吁人們重視女孩的教育。

1. 細(xì)節(jié)理解題。根據(jù)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，暴力不僅可以影響孩子的身體，也能改變他們的DNA,也能導(dǎo)致改變同期年齡的老化。

2. 細(xì)節(jié)理解題。根據(jù)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，可以阻止染色體中的DNA分裂。根據(jù)第二段中Scientists measured this by studying the ends of children?s chromosomes(染色體), called telomeres,科學(xué)家們通過研究孩子們的染色體的末端來檢測，可知A錯誤；根據(jù)第三段中的They get shorter each time a cell divides, until a cell cannot divide any more and dies每次一個細(xì)胞分化就會變得更短，直到細(xì)胞不能再次分化并死亡。.可知C、D錯誤。故選B

3. 推理判斷題。根據(jù)第五段最后一句in cells obtained by swabbing the insides of their cheeks?at ages 5 and 10.細(xì)胞包含在5到10歲的臉頰里擦拭�？梢酝浦狟錯誤；由第六段Telomeres shortened faster in kids exposed to two or more types of violence,在孩子兩種或兩種以上類型的暴力中，端粒會變短的速度更快�？芍狢 錯誤；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.研究建議，這些孩子希望可以改善年齡老化的疾病，例如心臟病或者失憶，比同齡的人要早7到10年�？芍�選D。

4. 主旨大意題，根據(jù)全文的內(nèi)容可知，文章描述了主要說明暴力會加速DNA中端粒的變短而讓孩子們提前衰老，而A項則很好地概括了文章大意，故選A。

考點(diǎn)：科普類文章閱讀。