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 (端粒), 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 by wiping 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 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 a 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 memory

B. violence can speed up a child’s aging

C. violence leaves scars on a child’s mind

D. hardship has an effect on a child’s mind

2.What does the underlined word “they” in Paragraph 3 refer to?

A. Telomeres.    B. Children.

C. Chromosomes.    D. DNA sequences.

3.What can be inferred from the text?

A. Violence can cause quick cell death in children’s body.

B. Telomeres can help prevent chromosomes from separating.

C. Children who have shorter telomeres have heart attacks later.

D. Being treated badly will make a child’s telomeres shorten faster.

4.What is the best title for the text?

A. Violence and Telomeres

B. The Function of Telomeres

C. Violence Makes Children Aging

D. DNA Influences Children’s Growth

Answer

1.B

2.A

3.D

4.C

【解析】本文主要讲述暴力不仅对孩子的身体有长久的影响，还会引起DNA变化，导致过早老化。

1.Ｂ

细节理解题。由文中的“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.”可知，暴力会改变孩子的DNA，导致相当于七到十年的过早衰老的变化，故选Ｂ。

2.Ａ

词义猜测题。由文中的“Telomeres are special DNA sequences which prevent the DNA in chromosomes from separating.”可知，“ｔｈｅｙ”指的是Telomeres。

3.Ｄ

推理判断题。根据第六段中Telomeres shortened faster in kids exposed to two or more types of violence, says Shalev. Unless that pattern changes,可知被虐待会使孩子的Telomeres缩短速度更快。故选Ｄ。

4.Ｃ

标题归纳题。文中主要讲的是一项新研究表明，暴力不仅在孩子的身体上留下长期的伤疤，而且还会改变孩子的DNA，导致其过早衰老。故Ｃ项作为标题最佳