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Can people change their skin color without suffering like pop king Michael Jackson? Perhaps yes.Scientists have found the gene that determines skin color.
The gene comes in two versions, one of which is found in 99 per cent of Europeans.The other is found in 93 t0 100 per cent of Africans, researchers at Pennsylvania State University report in the latest issue of Science.
Scientists have changed the color of a dark - striped zebrafish(斑马鱼) to uniform gold by inserting a version of the pigment(色素) gene into a young fish.As with humans, zebrafish skin color is deter-mined by pigment cells，which contain melanin(黑色素).The number, size and darkness of melanin perpigment cell determine skin color.
It appears that, like the golden zebrafish, light - skinned Europeans also have a mutation (变异) in the gene for melanin production.This results in less pigrnented skin.
However, Keith Cheng, leader of the research team, points out that the mutation is different in hu-man ancl zebrafish genes.
Humans acquired dark skin in Africa about l.5 million years ago to protect bodies from ultra - violetrays of the sun. which can cause skin cancer.
But when modem humans leave Africa to live in northem latitudes, they need more sunlight on their skin to produce vitamin D. So the related gene changes, according to Cheng.
Asians have the same version of the gene as Africans, so they probably acquired their light skin through the action of some other gene that affects skin color, said Cheng.
The new discovery could lead to medical treatments for skin cancer.lt also could lead to research in-to ways to change skin color without damaging it like chemical treatment did on Michael Jackson.
56.Scientists have done an experiment on a dark -striped zebrafish in order to
A.fincl the different genes o humans'
B.prove the humans' skin color is determined by the pigment gene
C.find out the reason why the Africans' skin color is dark
D.fincl out the ways of changing people's skin color
57.lt can be inferred from the passage that .
A.nowadays people who want to change their skin color have to suffer 8 lot from the damage caused by the chemical treatment
B.Europeans and Africans have the same gene
C.the new discovery could help to find medical treatments for skin cancer
D.there are two kinds of genes
58.The passage mainly tells us that .
A.scientists have found out that people's skin color is determined by the gene
B.the new discovery could lead to research into ways to change skin color safely
C. pop king Michael Jackson often changed his skin color as he liked
D.people can not change their skin color without any pain
59.The reason why Europeans are light - skinned is probably that .
A.they are bom light - skinned people
B.light - skinned Europeans have mutation in the gene for melanin production
C. th ey have fewer activities outside
D.they pay much attention to protecting their skin
60.The writer's attitude towarcls the discovery is .
A.neutral B.negative C.indifferent D.positive
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family home for a while. Many parents will say no to this demand. But experts say it might be a good idea
to let your teens live with a friend or relative.
"It was the break I need at the time," said Richant Lerner. He is talking about the time he spent living
with grandmother when he was 15.
"It allowed me to be a different person than I was with my parents," Lerner said. He now heads the
Institute (学会)for Children, Youth and Families at Michigan State University. Experts say teens living away
from their families can test new ways of thinking and getting along with people. They may see new solutions
to problems.
This is different from running away, the experts stress (强调). Runaways are often feeing serious
problems.
Some teens who want some time away from family attend a structured summer program. Others live for
a while with a relative or with the family of a friend. If there is a conflict (冲突) at home, having a teen live
elsewhere can benefit other family members. It gives everyone space to develop better relationships.
Joseph Kett teaches history at the University of Virginia in Charlottesville. He says living at home until the
late years has become the norm (准则) only in recent times. "In the 17 th century, children were often sent to
live in other people's homes when they were about 10 or 11," he said.
B. let them live for a while away from their families
C. send for a doctor
D. keep them in the house
B. played
C. organized
D. drunk
B. teens never made friends with each other
C. teens never went to school
D. teens often left their parents
B. often worry parents and teachers
C. are very popular
D. are accepted by people
读写任务（共1题，满分25分）
阅读下面的短文，然后按照要求写一篇150词左右的英语短文。
There is no doubt that watching television can influence the way that people behave. Moreover, it seems that people are spending more and more time watching some sort of visual entertainment, whether it is television, a video tape or a DVD. Therefore, the effects of visual media cannot be ignored.
One obvious effect of these media is that watching them induces people to buy certain products. Television advertising is widespread and, nowadays, even movie theaters permit advertisements. Another way TV and the movies affect people is that they give people either a broader view of the world or a distorted one, depending on what type of program they watch. Those who watch news and educational program can learn many new things while those who watch primarily entertainment shows may come to believe that most people in the world possess great wealth and good looks. It may make them become dissatisfied with their own lives. Finally, perhaps the most susceptible viewers are children, who may be unable to tell fact from fiction and may try to imitate acts that they see on TV or in the movies. And this is just what most parents and our society are worried about.
With the every-increasing popularity of video entertainment, we must pay attention to these effects.
[写作内容]
1.以约30个词概括短文的要点；
2.然后用约120个英语单词写一篇短文，就“电视等媒体给人们带来的影响”发表你的看法，短文必须包括以下要点：
a)电视等媒体给人们带来娱乐的同时也带来了哪些负面影响；
b)谈谈你是如何处理看电视等娱乐活动的；
c)就应该处理娱乐提一些自己的看法。
[写作要求]
(1)可以使用实例或其他论述方法支持你的观点，也可以参照阅读材料的内容，但不得直接引用原文中的句子；
(2)标题自定。