Can peo
ple 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. Thi
s results in less pigmented skin.
However, Keith Cheng, leader of the research team, points out that the mutation is dif ferent 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 vit amin D. So the related gene changes, according to Cheng.
Asians have the same version of the gene as Africans, so they pr obably 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 treat
ment did on Michael Jackson.. The passage mainly tells us that ________.
| A．people can not change their skin colour without any pain |
| B．the new discovery could lead to search into 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 |
. 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 peopl’s skin colour |
. 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 melanosome production |
| C．they have fewer activities outside |
| D．they pay much attention to protecting their skin |
Do other countries’ students also have so much homework? What do they usually do in their free time? You may feel curious about them.
On April 8, a report came out on the lives of high school students in China, Japan, South Korea and the US. It surveyed around 6,200 students from the four countries last year. You will find the answers to many of your questions in this report.
Who studies hardest?
Chinese students spend the most time studying. Nearly half of Chinese students spend more than two hours on their homework every day. That’s much more than students of the US (26.4%), Japan (8.2%) and South Korea (5.2%).
Who sleeps most often in class?
Japanese students fall asleep in class most often. About 45% of them said they sometimes doze off in class. In South Korea, it’s 32%; in the US, 21%; and 5% in China. South Korean students don’t like taking notes. About 70% said they write down what the teacher says in class, many fewer than in Japan (93%), China (90%) and the US (89%).
Who is the most distracted (分心的)?
American students are the most active in class, but also the most distracted: 64.2% said they chat with friends in class; 46.9% said they eat snacks in class; and 38.9% said they send e-mails or read unrelated books in class.
What do they do after school?
In their spare time, most Chinese students study or surf the Internet. Most American students hang out with their friends. Most Japanese students do physical exercise. Most Korean students watch TV. The report is about ___________.
| A．the countries | B．the subjects |
| C．the students’ lives | D．the high schools |
What country isn’t mentioned in the report?
| A．The US | B．South Korea | C．Japan | D．India |
_____of the Chinese students spend more than two hours on their homework.
| A．26.4% | B．8.2% | C．5.2% | D．48.6% |
The phrase doze off means _____.
| A．be half asleep. | B．get up | C．eat snacks | D．send emails |
Proudly reading my words, I glanced around the room, only to find my classmates with big smiles on their faces and tears in their eyes. Confused, I glanced toward my stone-faced teacher. Having no choice, I slowly raised the report I had worked on, hoping to hide myself. “What could be causing everyone to act this way?”
Quickly, I flashed back to the day Miss Lancelot gave me the task. This was the first real task I received in my new school. It seemed simple: go on the Internet and find information about a man named George Washington. Since my idea of history came from an ancient teacher in my home country, I had never heard of that name before. As I searched for the name of this fellow, it became obvious that there were two people with the same name who looked completely different! One invented hundreds of uses for peanuts, while the other led army across America. I stared at the screen, wondering which one my teacher meant. I called my grandfather for a golden piece of advice: flip (掷) a coin. Heads—the commander, and tails—the peanuts guy. Ah! Tails, my report would be about the great man who invented peanut butter, George Washington Carver.Weeks later, standing before this unfriendly mass, I was totally lost. Oh well, I lowered the paper and sat down at my desk, burning to find out what I had done wrong. As a classmate began his report, it all became clear, “My report is on George Washington, the man who started the American Revolution.” The whole world became quiet! How could I know that she meant that George Washington?
Obviously, my grade was terrible. Heartbroken but fearless, I decided to turn this around. I talked to Miss Lancelot, but she insisted: No re-dos; no new grade. I felt that the punishment was not justified, and I believed I deserved a second chance. At last, I worked very hard for the rest of the school year.
Ten months later, that chance came as I found myself sitting in the headmaster’s office with my grandfather, now having a completely different conversation. I smiled and flashed back to the embarrassing moment at the beginning of the year as the headmaster informed me of my chance to skip the sixth grade. Justice is sweet! What did the author’s classmates think about his report?
| A．Complex. | B．Funny. | C．Boring. | D．Puzzling. |
Why was the author confused about the task?
| A．He was unfamiliar with American history. |
| B．He followed the advice and flipped a coin. |
| C．He forgot his teacher’s instruction. |
| D．He didn’t know why the teacher gave such a task. |
In the end, the author turned things around _______.
| A．by redoing his task |
| B．through his own efforts |
| C．with the help of his grandfather |
| D．under the guidance of his headmaster |
My house is made of wood, glass and stone. It is also made of software.
If you come to visit, you'll probably be surprised when you come in: Someone will give you an electronic PIN to wear. The PIN tells the house who you are and where you are. The house uses this information to give you what you need. When it's dark outside, the PIN turns on the lights near you, and then turns them off as you walk away from them. Music moves with you, too. If the house knows your favorite music, it plays it for you. The music seems to be everywhere, but in fact other people in the house hear different music or no music. If you get a telephone call, only the nearest telephone rings.
Of course, you are also able to want something. There is a home control console (控制台) which is a small machine that turns things on and off around you.
The PIN and the console are new ideas, but they are in fact like many things we have today. If you want to go to a movie, you need a ticket. If I give you the key to my car, you can use my car. The car works for you because you have the key. My house works for you because you wear the PIN or hold the console.
I believe that in ten years from now, most new houses will have the systems that I've put in my house. The systems will probably be even bigger and better than the ones I've got.
I like to try new ideas. I know that some of my ideas will work better than others'. But I hope that one day I will stop thinking of these systems as new, and ask myself instead, ”How did I live without them?”The writer’s house is made of the following EXCEPT_________.
| A．bamboo | B．wood | C．glass | D．software |
What is the writer most likely to be according to the passage?
| A．An IT expert. | B．A famous doctor. |
| C．A sportsman. | D．An experienced teacher. |
The writer's new house is different from ordinary ones mainly because______________.
| A．it has your favorite music following you |
| B．you can make a telephone call anywhere |
| C．the writer is able to change his new idea into practice |
| D．it is controlled by computers |
What does the passage mainly discuss?
| A．How to develop a new system. | B．The function of the PIN. |
| C．How great the computers are. | D．Easy life in the future. |
When was the last time your family sat down together to have a dinner?
The speed at which we live today no longer allows for slow eating habits. Most people work long hours. There is lots of fast food and eating out is now on the increase. Often, food is eaten in front of the television in silence, or a child eats alone in front of the computer.
When I was a child, every evening around the same time, one of the children would be asked to set the table, and then we'd go and wash our hands: before the meal. This was the time of day when we would talk about our day at school. But now things have changed a lot.
A family environment plays an important role for children in learning to communicate with others and understanding table manners, such as waiting for others to finish before leaving the table and not speaking with a mouth full of food. Parents’ likes and dislikes of a certain food will also influence a child's own likes and dislikes. Studies have shown that children who often eat with their families have better results at school than children who eat with their families less than twice a week.
Regular meal times give children the chance to discuss their problems with family members. They can also learn to respect others around the table. Talking to your children over dinner is the best way of having their-trust. Children learn good eating habits from their parents at a very young age. Family meals are important. Prepare them for your children.Some families eat less together because __________.
| A．most children live in a school |
| B．people are busy with their work |
| C．table manners change a lot |
| D．food in the restaurant is better |
Children who often eat with their families _________.
| A．turn out to do better in their studies |
| B．prefer to share food with others |
| C．show concerns about families |
| D．are interested in cooking |
Which word can best describe the writer's attitude towards eating together with families?
| A．Supportive. | B．Doubtful. | C．Worried. | D．Grateful. |
Which would be the best title of the passage?
| A．Table manners of a family | B．The importance of meals |
| C．Why should the family eat together? | D．How to choose food for your family? |
Welcome to the Ambassador Hotel. To make your stay as enjoyable as possible, we hope you can make full use of our facilities（设备）.
Dining Room
Breakfast is served in the dining room from 8 a.m. to 9:30 a.m. The room staff will bring a breakfast tray to your room at any time after 7 a.m. Please fill out a card and hang it outside your door when you go to bed.
Lunch: 12:00 a.m. to 2:30 p.m.
Dinner: 7:30 p.m. to 9:00 p.m.
Room Service
This operates 24 hours a day; phone the Reception Desk, and your message will be passed on to the room staff.
Telephones
To make a phone call, dial 0 for Reception and ask to be connected. We apologize for delays in putting calls through when the staffs are very busy. There are also public telephone boxes near the Reception Desk. Early calls should be booked with Reception.
Laundry
We have a laundry in the hotel, and will wash, iron and return your clothes within 24 hours. Ask the room staff to collect them.
Bar
The hotel bar is open from 12 a.m. to 2 p.m. and 7 p.m. to 1 a.m.You would see this notice ___________.
| A．in a hotel bar |
| B．in a hotel dining room |
| C．in a bedroom of a large hotel |
| D．in the entrance of a small family hotel |
What time can you have breakfast in the dinning room?
| A．6:50 a.m. | B．7:00 a.m. | C．7:30 a.m. | D．8:30 a.m. |
What should you do when you come back to the hotel to make an important call and see a lot of people around the Reception Desk?
| A．Go to your room and phone from there. |
| B．Ask at the Reception Desk. |
| C．Go to the public telephone boxes. |
| D．Go out again and look for a private phone. |
What should you do if you want to have your trousers washed?
| A．Ask the room staff to collect them to the laundry. |
| B．Go to the hotel bar. |
| C．Hang a message outside your door. |
| D．Ask the room staff to clean them for you. |