Todaywearegoingtotalkaboutimpo-优题课

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．
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．

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

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

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．

She may have lacked a home, but now this teen has top honors．
A 17-year-old student who spent much of high school living around homeless shelters — and sometimes sleeping in her car — today graduated and spoke on behalf of her class at Charles Drew High School in Clayton County, Ga．, just outside of Atlanta．
Chelsea Fearce held a 4．466 GPA and scored 1900 on her SATs despite having to use her cellphone to study after the shelter lights were turned off at night．
“I know I have been made stronger．I was homeless．My family slept on cushions on the floor and we were lucky if we got more than one full meal a day．Getting a shower, food and clean clothes was an everyday struggle,” Fearce said in a speech she gave at her graduation ceremony．Fearce overcame her day-to-day struggles by focusing on a better day．“I just told myself to keep working, because the future will not be like this anymore,” she told WSBTV．
Fearce, one of five children, grow up in a family that sometimes had an apartment to live in, but at other times had to live in homeless shelters or even out of their car, if they had one．“You’re worried about your home life and then worried at school．Worry about being a little hungry sometimes and go hungry sometimes．You just have to deal with it．You eat what you can, when you can．”
To our surprise, Fearce overcame the difficulties and even tested high enough to be admitted into college half way through her high school career．She starts college next year at Spelman College as a junior where she is planning to study biology, pre-med (医学预科)．“Don’t give up．Do what you have to do right now so that you can have the future that you want,” Fearce said．
How did Fearce go on with her study without access to lights?

A．By the car light．

B．By her cellphone．

C．By lights out of shelters．

D．By moonlight．

When Fearce starts college at Spelman College, she will _____．．

A．have graduated earlier from high school than normal

B．be a 17-year-old student from a poor family

C．have a home without sleeping in her car or shelters

D．have raised enough money to go to college

What lesson can we learn from Fearce’s experience?

A．Knowledge can change your fate．

B．Don’t give up, and tomorrow will be better．

C．Whatever is worth doing is worth doing well．

D．He that will not work shall not eat．

Drinking alcohol is a socially acceptable behavior in many parts of the world．Some medical experts say light drinking may even be good for your health, especially for the heart．But they say such health benefits should be compared to the many health risks connected with alcohol use．
Some research suggests that having one to two drinks of alcohol a day may offer some health benefits．Several large studies have shown that this type of moderate(适量的) drinking may lower the risk of heart disease and other diseases．
A study last year suggested that drinking small amounts of red wine may help lower the risk of breast cancer in women．Researchers at Medical Center in California studied 36 women．Each woman drank a glass of red or white wine every day for almost a month．Researchers collected blood samples from the women two times a month to measure their hormone(激素) levels．The next month the women who drank red wine were told to drink white wine instead．The white wine drinkers were told to drink red wine．The researchers found that the women who drank red wine had lower levels of the female hormone than the white wine drinkers．They said red grapes have chemicals that may help to lower the risk of breast cancer．
However, recent studies suggested that even small amounts of alcohol may generally increase the risk of breast cancer in women．They found that women who drink four small glasses of wine a week increase their risk of breast cancer by 15 percent．
Many studies have examined the harmful effects of alcohol use on the body．Alicia Ann Kowalchuk serves as medical director, saying “Healthy use for adults --- that's men under age 65 --- is no more than 4 drinks in a day and no more than 14 drinks in a week．And for women of all ages, it's no more than 7 drinks in a week and no more than 2 drinks in a day．” She says too much alcohol use has been linked to liver diseases, and many other cancers．
How did the researchers carry out their study?

A．By following an example．

B．By listing facts．

C．By collecting information worldwide．

D．By comparing tested objects．

Which of the following is the most beneficial to women with breast cancer?

A．A glass of white wine per day．

B．A glass of red wine per day．

C．Small amounts of alcohol per day．

D．Four small glasses of wine per day．

Which of the following shows the structure of the passage?

What is the best title of this passage?

A．Drinking alcohol is popular in many parts of the world

B．Alcohol drinking can be both good and bad for you

C．Drinking alcohol a day may give your health some benefits．

D．Alcohol drinking may do harm to your health

Life is filled with challenges．As we get older we come to realize that those challenges are the very things that shape us and make us who we are，it is the same with the challenges that come with friendship．When we are faced with a challenge，we usually have two choices．We can try to beat it off, or we can decide that the thing presenting the challenge isn’t worth the trouble and call it quits．Although there are certainly times when calling it quits is the right thing to do，in most cases all that is needed is commitment(承诺)and communication．
When we are committed to something， it means that no matter how painful or how uncomfortable something is，we will always choose to face it through instead of running away from it．Communication is making a space for discussion and talking about how you feel as opposed to just saying what the other person did wrong．If you can say to a friend，“I got my feelings hurt．” rather than“You hurt my feelings．”you are going to be able to solve the problem much faster．
In dealing with many challenges that friendship will bring to you, try to see them for what they are：small hurdles you need to jump or get through on your way through life．Nothing is so big that it is impossible to get over, and hurt only serves to make us stronger．It is all part of growing up，it happens to everyone，and some day you will look back on all of this and say,“Hard as it was，it made me who I am today．And that is a good thing．”
What is the underlined word“committed”can be replaced by ____________．
A．devotedB satisfied
C．smpdsedD．interested
It can be inferred from the text that _____________．

A．friendship needs challenges

B．challenges shape our character

C．small hurdles aren’t worth the trouble

D．commitment promotes friendship

The writer suggests that _____________ when faced with a challenge．

A．one should call it quits

B．one should temporarily run away from it

C．one should be committed and communicable

D．one should lay it a side for a while

According to the passage，if your friend hurts your feelings，you are well advised to _______________．

A．forget it

B．talk to him／her about it directly

C．communicate properly with him／her

D．run away from it

The whole passage is centered on the relationship between _____________．

A．friendship and challenges

B．commitment and communication

C．communication and friendship

D．challenges and the ways to get through

It is widely acknowledged that it is by no means an easy task to bring up a child well．And our ancestors already understood it well．“It takes an entire village to raise a child．”That’s an old proverb that is being quoted more and more often these days．And I’m pleased about that．
Today，more and more schools are reaching out to involve parents, community members and businesses to help shape a child’s future．
Parents need to be involved in their children’s education in many ways．Helping children with homework and studying，going on a field trip，teaching a craft（手工艺）or coaching a child's sports team are all great ways to be involved with your child's education．And don’t forget to communicate with teachers — they need and respect your input．Studies show that children learn more and schools function better when parents and schools work together．It’s important to stay in touch with your child's education all through his or her school career．
Communities can help children create and achieve new goals．Help with homework, read to a child，coach a children's team，or provide emotional support．Help solve problems and build self-esteem（自尊）．Kids need role models and advisers can be role models by sharing their experiences and wisdom．
Businesses can also help shape our children’s future．invite a class from your local school to visit your workplace．You may be providing a glimpse that opens a new world of possibilities．Show students what goes on during a typical day．Give a mini course for students：how to use a computer；how products are made；how machinery works．You may have a developing electrician，teacher，nurse，or even a newspaper reporter on your hands．
It really does take an entire village to raise a child．So share the responsibility— and the joy— of bringing a child to his or her full potential．
The implied advice in the proverb“It takes an entire village to raise a child．” is that ____________．

A．All the people in a village should give food to a child

B．More than one party is responsible for a child’s future

C．Children should be brought up in the village where they were born

D．Schools should be set up in the village where a child was raised

According to the text，_____________ should talk with teachers to keep in touch with children’s growth？

A．community members

B．businesses

C．organizations

D．parents

The text was written mainly for ______________．

A．newspaper reporters and developing electricians

B．school teachers and students

C．parents and members in organizations

D．education experts and government officials

Students can get developed in practical working s kill through ___________．
A．business training
B community activities
C．parental involvement
D．school teaching
Which of the following can be the main idea of idea text？

A．Parents play an important part in children’s education．

B．Communities have no effect on the way to new and high ideals．

C．Parents and other organizations should all be responsible for children’s growth

D．Businesses may arrange softie training courses for students．