Can people change their skin colour without s...

Can people change their skin colour without suffering like pop king Michael Jackson? Perhaps yes. Scientists have found the gene that determines skin colour. The gene comes in two versions, one of which is found in 99 per cent of Europeans. The other is found in 93 to 100 per cent of Africans, researchers at Pennsylvania State University report in the latest issue of Science.

Scientists have changed the colour of a dark-striped zebra fish to uniform gold by inserting a version of the pigment (色素) gene into a young fish. As with humans, zebra fish skin colour is determined by pigment cells, which contain melanosomes (黑色素体). The number, size and darkness of melanosomes per pigment cell determines skin colour.

It appears that, like the golden zebra fish, light-skinned Europeans also have a mutation (突变)in the gene for melanosome production. This results in less pigmented skin. However, Keith Cheng, leader of the research team, points out that the mutation is different in human and zebra fish genes.

Humans acquired dark skin in Africa about 1.5 million years ago to protect bodies from ultra-violet rays of the sun, which can cause skin cancer. But when modern humans leave Africa to live in northern 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 colours, said Cheng.

The new discovery could lead to medical treatments for skin cancer. It also could lead to research into ways to change skin colour without damaging it like chemical treatment done on Michael Jackson.

1.According to the passage, scientists have found .

A. people living in northern latitudes need more sunlight

B. the reason why people change their skin colour

C. the reason why people get skin cancer

D. the gene that determines skin colour

2.We can infer from the passage that ________.

A. people like to change their skin colour

B. a mutation in the gene for melanosome production is different in human and zebra fish gene

C. people will be able to change their skin colour without chemical treatment in the future

D. skin cancer can be cured now

3.Which of the following is NOT mentioned according to the passage?

A. The version of the pigment gene of Asians and that of Africans are the same.

B. Scientists have succeeded in turning the colour of a dark-striped zebra fish into uniform gold.

C. Dark skin can protect bodies from utral-violet rays of the sun.

D. People like pop king Michael Jackson.

4.The passage is probably taken from __________.

A. a novel         B. a science report

C. a story book       D. a science fiction

高三英语阅读理解中等难度题查看答案及解析

Can people change their skin colour without suffering like pop king Michael Jackson? Perhaps yes. Scientists have found the gene that determines skin colour.

The gene comes in two versions, one of which is found in 99 per cent of Europeans. The other is found in 93 to 100 per cent of Africans, researchers at Pennsylvania State University report in the latest issue of Science.

Scientists have changed the colour of a dark-striped zebrafish to uniform gold by inserting a version of the pigment(色素) gene into a young fish. As with humans, zebrafish skin colour is determined by pigment cells, which contain melanosomes(黑色素). The number, size and darkness of melanosomes per pigment cell determines skin colour.

It appears that, like the golden zebrafish, light-skinned Europeans also have a mutation(变异) in the gene for melanosome production. This results in less pigmented skin.

However, Keith Cheng, leader of the research team, points out that the mutation is different in human and zebrafish genes.

Humans acquired dark skin in Africa about 1.5 million years ago to protect bodies from ultra-violet rays(紫外线) of the sun, which can cause skin cancer.

But when modern humans leave Africa to live in northern 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 colour, said Cheng.

The new discovery could lead to medical treatments for skin cancer. It also could lead to research into ways to change skin colour without damaging it like chemical treatment did on Michael Jackson.

1.What is the main idea of the passage?

A. People can’t change their skin colour without any pain.

B. The new discovery helped find ways to change skin colour safely.

C. Pop king Michael Jackson often changed his skin colour as he liked.

D. Scientists have found out that people’s skin colour is determined by the gene.

2.It can be inferred from the passage that ________.

A. nowadays changing the skin colour with the chemical treatment has bad effect

B. Europeans and Africans have the same genes

C. the new discovery could help to find medical treatments for skin cancer

D. there are two kinds of skin genes

3.Scientists have done an experiment on a dark-striped zebra fish in order to ________.

A. find the different genes of humans

B. prove the humans’ skin colour is determined by the pigment gene

C. find out the reason why the Africans’ skin colour is dark

D. find out the ways of changing people’s skin colour

4.Which of the following statements is TRUE?

A. Michael Jackson died of skin damage caused by chemical treatment.

B. American blacks produce more vitamin D with their skin than others.

C. The gene determining skin colour exists widely in whites, blacks and Asians.

D. The melanosomes in the skin of blacks usually cause skin cancer more often.

高三英语阅读理解中等难度题查看答案及解析

Can people change their skin colour without suffering like pop king Michael Jackson? Perhaps yes．Scientists have found the gene that determines skin colour．

The gene comes in two versions, one of which is found in 99 per cent of Europeans．The other is found in 93 to 100 per cent of Africans, researchers at Pennsylvania State University report in the latest issue of Science．

Scientists have changed the colour of a dark-striped zebrafish to uniform gold by inserting a version of the pigment(色素) gene into a young fish．As with humans, zebrafish skin colour is determined by pigment cells, which contain melanosomes(黑色素)．The number, size and darkness of melanosomes per pigment cell determines skin colour．

It appears that, like the golden zebrafish, light-skinned Europeans also have a mutation(变异) in the gene for melanosome production．This results in less pigmented skin．

However, Keith Cheng, leader of the research team, points out that the mutation is different in human and zebrafish genes．

Humans acquired dark skin in Africa about 1．5 million years ago to protect bodies from ultra-violet rays(紫外线) of the sun, which can cause skin cancer．

But when modern humans leave Africa to live in northern 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 colour, said Cheng．

The new discovery could lead to medical treatments for skin cancer．It also could lead to research into ways to change skin colour without damaging it like chemical treatment did on Michael Jackson．

1.What is the main idea of the passage?

A． People can’t change their skin colour without any pain．

B． The new discovery helped find ways to change skin colour safely．

C． Pop king Michael Jackson often changed his skin colour as he liked．

D． Scientists have found out that people’s skin colour is determined by the gene．

2.It can be inferred from the passage that ________．

A． nowadays changing the skin colour with the chemical treatment has bad effect

B． Europeans and Africans have the same genes

C． the new discovery could help to find medical treatments for skin cancer

D． there are two kinds of skin genes

3.Scientists have done an experiment on a dark-striped zebra fish in order to ________．

A． find the different genes of humans

B． prove the humans’ skin colour is determined by the pigment gene

C． find out the reason why the Africans’ skin colour is dark

D． find out the ways of changing people’s skin colour

4.Which of the following statements is TRUE?

A． Michael Jackson died of skin damage caused by chemical treatment．

B． American blacks produce more vitamin D with their skin than others．

C． The gene determining skin colour exists widely in whites, blacks and Asians．

D． The melanosomes in the skin of blacks usually cause skin cancer more often．

高三英语阅读理解中等难度题查看答案及解析

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 to 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 determined by pigment cells, which contain melanin (黑色素). The number, size and darkness of melanin per pigment 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 pigmented skin.

However, Keith Cheng, leader of the research team, points out that the mutation is different in human and zebrafish genes.

Humans acquired dark skin in Africa about 1.5 million years ago to protect bodies from ultra-violet rays of the sun (太阳光紫外线), which can cause skin cancer.

But when modern humans leave Africa to live in northern 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. It also could lead to research into ways to change skin color without damaging it like chemical treatment did on Michael Jackson.

1.The passage mainly tells us that ________.

A. people can not change their skin color without any pain

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. scientists have found out that people’s skin color is determined by the gene

2.It can be inferred from the passage that ________.

A. nowadays people who want to change their skin color have to suffer a 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

3.Scientists have done an experiment on a dark-striped zebrafish in order to ________.

A. find the different genes of 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. find out the ways of changing people’s skin color

4.The reason why Europeans are light-skinned is probably that _____

A. they are born light-skinned people

B. light-skinned Europeans have mutation in the gene for melanin production

C. they have fewer activities outside

D. they pay much attention to protecting their skin

5.The writer’s attitude towards the discovery is ________.

A. neutral B. negative        C. positive       D. unconcerned

高三英语阅读理解中等难度题查看答案及解析

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 percent of Europeans. The other is found in 93 to 100 percent of Africans, researchers at Pennsylvania State University report in the latest issue of Science.

Scientists have changed the color of a dark-striped zebra-fish（斑马鱼） to uniform gold by inserting a version of the pigment (色素) gene into a young fish. As with humans, zebra-fish skin color is determined by pigment cells, which contain melanin (黑色素). The number, size and darkness of melanin per pigment cell determine skin color.

It appears that, like the golden zebra-fish, light-skinned Europeans also have a mutation (变异) in the gene for melanin production. This results in less pigmented skin.

However, Keith Cheng, leader of the research team, points out that the mutation is different in human and zebra-fish genes.

Humans acquired dark skin in Africa about 1.5 million years ago to protect bodies from ultra-violet rays of the sun (太阳光紫外线), which can cause skin cancer.

But when modern humans leave Africa to live in northern 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. It also could lead to research into ways to change skin color without damaging it like chemical treatment did on Michael Jackson.

1.The passage mainly tells us that ________.

A. people can not change their skin color without any pain

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. scientists have found out that people’s skin color is determined by the gene

2.It can be inferred from the passage that _____________.

A. nowadays people who want to change their skin color have to suffer a 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

3.Scientists have done an experiment on a dark-striped zebra-fish in order to _____________.

A. find the different genes of 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. find out the ways of changing people’s skin color

4. The reason why Europeans are light-skinned is probably that _____________.

A. they are born light-skinned people

B. light-skinned Europeans have mutation in the gene for melanin production

C. they have fewer activities outside

D. they pay much attention to protecting their skin

5.The writer’s attitude towards the discovery is ______________.

A. neutral　　　　　　　　　 　　　　　 B. negative　　　　　　　　　 　　　　 C. positive　　　　　 D. unconcerned

高三英语阅读理解困难题查看答案及解析

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 to 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 determined by pigment cells, which contain melanin (黑色素). The number, size and darkness of melanin per pigment 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 pigmented skin.

However, Keith Cheng, leader of the research team, points out that the mutation is different in human and zebrafish genes.

Humans acquired dark skin in Africa about 1.5 million years ago to protect bodies from ultra-violet rays of the sun (太阳光紫外线), which can cause skin cancer.

But when modern humans leave Africa to live in northern 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. It also could lead to research into ways to change skin color without damaging it like chemical treatment did on Michael Jackson.

1. The passage mainly tells us that ________.

2. It can be inferred from the passage that ________.

3.Scientists have done an experiment on a dark-striped zebrafish in order to ________.

4.The reason why Europeans are light-skinned is probably that _____

5.The writer’s attitude towards the discovery is ________.

高三英语阅读理解中等难度题查看答案及解析

Millions of people around the world suffer from a painful addiction to biting their nails， which can be harder　　　　 than smoking cigarettes．

A．to be quitted　　　　 B．to quit

C．to have quitted　　　　 D．to quitting

高三英语单项填空中等难度题查看答案及解析

Millions of people around the world suffer from a painful addiction to biting their nails，which can be harder________than smoking cigarettes．

A．to be quitted    B．to quit

C．to have quitted    D．to quitting

高三英语单项填空中等难度题查看答案及解析

Quite a few people like traveling, for it can increase their knowledge and broaden their _____．

高三英语单项填空中等难度题查看答案及解析

Dogs are known for their sense of smell．They can find missing people and things like bombs and illegal drugs．Now a study suggests that the animal known as man’s best friend can even find bladder（膀胱）cancer．

Cancer cells are thought to produce chemicals with unusual odors（气味）．Researchers think dogs have the ability to smell these odors, even in very small amounts, in urine（尿）．The sense of smell in dogs is thousands of times better than in humans．

The study follows reports of cases where, for example, a dog showed great interest in a growth on the leg of its owner．The man was later found to be skin cancer．Carolyn Willis led a team of researchers at Amersham Hospital in England．They trained different kinds of dogs for the experiment．The study involved urine collected from bladder cancer patients, from people with other diseases and from healthy people．Each dog was tested 8 times．In each test there were 7 samples for the dogs to smell．The dog should signal the one from a bladder cancer patient by lying down next to it．Two cocker dogs were correct 56 percent of the time．But the scientists reported an average success rate of 41 percent．The British Medical Journal published the research．In all, 36 bladder cancer patients and 108 other people took part．During training, all the dogs reportedly even identified（认出）a cancer in a person who had tested healthy before the study．Doctors found a growth on the person’s right kidney（肾）．Carolyn Willis says dogs could help scientists identify the combined chemicals produced by bladder cancer．That information could then be used to develop machines to test for the chemicals．The team also plans to use dogs to help identify markers for other kinds of cancer．

49．What’s the general idea of the text?

A．Dogs have a good sense of smell        B．Dogs can help cure cancer

C．Dogs can smell cancer                 D．Dogs help perform experiments

50．According to the text, people who suffer bladder cancer_____

A．often have urine with unusual smell                       B．probably smoke cigarettes in their life

C．can easily make dogs lie down

D．are likely to die within nine years

51．The underlined word “involved” in the text is closest in meaning to _____．

A．showed            B．used          C．proved       D．preferred

52．What can we conclude from the last paragraph?

A．Dogs can only smell bladder cancer．

B．Dogs have a good knowledge of cancer．

C．Cancer doesn’t have any sign in the beginning．

D．Scientists might invent some equipment to test cancer．

高三英语阅读理解中等难度题查看答案及解析