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 (過早老化).

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 (序列) 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 from 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 hardship imprints itself in our chromosomes, says Charles Nelson, a professor of pediatrics and neuroscience at Harvard Medical School.

1.The new study has found that ________.

A. violence leaves scars on a child’s mind

B. violence can speed up a child’s aging

C. hardship can change a child’s aging

D. hardship has a long-term effect on children

2.According to the text, telomeres ________.

A. probably cause a cell to divide quickly

B. can help prevent DNA from separating

C. can make a cell die quickly

D. become shorter before they die

3.All of the following things can shorten telomeres EXCEPT ________.

A. maltreatment B. radiation

C. smoking D. exercising

4.Which of the following is TRUE, according to the text?

A. Researchers measured the children’s telomeres from their legs in the study.

B. Kids interviewed in the study are exposed to two or more types of violence.

C. Children who have shorter telomeres may suffer from a heart attack earlier.

D. Victims of domestic violence have no hopes of lengthening their telomeres.

5.What is the best title for the text?

A. Violence aging children’s DNA

B. Children’s changing DNA patterns

C. Violence and children

D. The function of telomeres

Answer 1

1.B

2.B

3.D

4.C

5.A

【解析】

試題分析：本文主要講述暴力不僅對孩子的身體有長久的影響，還會引起DNA變化，導(dǎo)致過早老化

1. 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 (過早老化).這份新的研究指出暴力不僅給孩子身體造成長久傷痕，而且改變其DNA引起過早老化，可知暴力會加速孩子變老，故選B

2. are special DNA sequences (序列) which prevent the DNA in chromosomes from separating端粒防止DNA分離，故選B

3. factors have been found to shorten telomeres, including smoking, radiation and psychological stresses such as being treated badly可知只有鍛煉不能使端粒變短，故選D

4. 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端粒更短的孩子，研究表明，更可能發(fā)展出老化疾病如心臟病，故選C

5.

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