四级听力复合听写模拟训练第17套

　　Section C

　　Directions: In this section, you will hear a passage three times. When the passage is read for the first time, you should listen carefully for its general idea. When the passage is read for the second time, you are required to fill in the blanks numbered from 36 to 43 with the exact words you have just heard. For blanks numbered from 44 to 46 you are required to fill in the missing information. For these blanks, you can either use the exact words you have just heard or write down the main points in your own words. Finally, when the passage is read for the third time, you should check what you have written.

　　注意：此部分试题在答题卡2上;请在答题卡2上作答。

　　Part III Section C

　　One of the genes that protects us from cancer may also help delay aging, according to a new study.

　　The findings could also one day lead to new drugs that prevent or fight cancer while healthy youth and life span, said Manuel Serrano, a researcher at the Spanish National Cancer Research Centre, who worked on the study.

　　Serrano said researchers engineered mice to have an extra copy of a key cancer-fighting gene called p53 and found it also played an important role in delaying aging.

　　Everyone agrees that the aging is produced by the of faulty cells, Serrano said. In other words, p53 delays aging for exactly the same reason that it prevents cancer.

　　cancer studies have shown that p53 can actually cause aging symptoms by killing too many cells when it goes into , but Serrano said his research strictly

　　the gene so that it turned on only when needed.

　　The gene did their job of producing a protein that kills damaged cancer cells. But the researchers found that mice with an extra copy of the genes This is the first anti-cancer gene tested for its effect on aging, Serrano said. The mice lived 16 percent longer in their average life span.

　　The p53 gene, when working properly,

　　If the gene is mutated or inactivated the control mechanism does not work.

　　Serrano also said that other research has shown that mice and worms that eat less have slower metabolisms and live longer. But his study offers evidence that

　　Section C

　　文章精要

　　本文主要介绍的是一项新的科学发现。有一种基因不仅能够抵抗癌细胞，还能够延缓衰老。科学家通过小白鼠实验发现，这种基因能降低癌症对它们身体的影响并且延长它们的寿命。虽然实验已证实吃得少能降低新陈代谢的速率，从而使小白鼠活得更久，然而得益于此种基因，它们能在不挨饿的情况下获得更长的寿命。

　　36.extending

　　37.genetically

　　38.accumulation

　　39.Previous

　　40.premature

　　41.overdrive

　　42.regulated

　　43.normal

　　44.actually lived longer even when stripping out the impact of having less cancer

　　45.makes sure that damaged cells destroy themselves and do not divide uncontrollably to cause

　　46.the mice can benefit from the extra copy of the genes without having to be starved

　　Section C

　　One of the genes that protects us from cancer may also help delay aging, according to a new study.

　　The findings could also one day lead to new drugs that prevent or fight cancer while extending healthy youth and life span, said Manuel Serrano, a researcher at the Spanish National Cancer Research Centre, who worked on the study.

　　Serrano said researchers genetically engineered mice to have an extra copy of a key cancer-fighting gene called p53 and found it also played an important role in delaying aging.

　　Everyone agrees that the aging is produced by the accumulation of faulty cells, Serrano said. In other words, p53 delays aging for exactly the same reason that it prevents cancer.

　　Previous cancer studies have shown that p53 can actually cause pre-mature aging symptoms by killing too many cells when it goes into overdrive, but Serrano said his research strictly regulated the gene so that it turned on only when needed.

　　The gene did their normal job of producing a protein that kills damaged cancer cells. But the researchers found that mice with an extra copy of the genes actually lived longer even when stripping out the impact of having less cancer.

　　This is the first anti-cancer gene tested for its effect on aging,Serrano said. The mice lived 16 percent longer in their average life span.

　　The p53 gene, when working properly, makes sure that damaged cells destroy themselves and do not divide uncontrollably to cause tumors. If the gene is mutated or inactivated the control mechanism does not work.

　　Serrano also said that other research has shown that mice and worms that eat less have slower metabolisms and live longer. But his study offers evidence that the mice can benefit from the extra copy of the genes without having to be starved.