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.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 |
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 |
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 |
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 |
The writer’s attitude towards the discovery is ______________.
| A．neutral | B．negative |
| C．positive | D．unconcerned |
Charlton Heston was born in 1923 in Evanston, Illinois. Charlton Heston discovered his interest in acting while performing in plays at his high school. He later spent two years studying theater at Northwestern University in Evanston, Illinois. But he left college to join the Army Air Forces during World War Two.
After the war, he found small roles in the theater as well as in television shows. His performance in a television version of the book Jane Eyre caught the attention of the Hollywood producer Cecil B. De Mille who later asked Heston to play the role of Moses in his movie The Ten Commandments which came out in 1956.This role made Heston famous and defined(明确) his career as a hero and leader. His face and body represented strength and heroism in many different roles. He played cowboys, soldiers and athletes.
The 1959 movie Ben Hur made Charlton Heston an even bigger star. Ben Hur won eleven Academy Awards, including Best Actor for Charlton Heston. Heston starred in many adventure movies during the 1960s. In the 1970s, Heston appeared in popular disaster movies like Earthquake, Skyjacked and Airport 1975.
Charlton Heston was also very active in the movie industry. He worked to help set up the American Film Institute. In 1977 he was honored for his service in the industry. He received the Jean Hersholt Humanitarian Award from the Academy of Motion Picture Arts and Sciences. In 1997 he was awarded a Kennedy Center Honor. And, in 2003, President Bush gave Charlton Heston a Presidential Medal of Freedom, the nation’s highest civilian honor.
In 2000, Charlton Heston issued a statement announcing that he had an Alzheimer’s disease. He died in 2008 at his home in Beverly Hills, California.
| A．Heroes. | B．Cowboys. | C．Soldiers. | D．Athletes. |
| A．Jane Eyre. | B．Earthquake. |
| C．Ben Hur. | D．The Ten Commandments. |
| A．He began to show his talent in Ben Hur. |
| B．He used to be a soldier. |
| C．He was once awarded by Kennedy. |
| D．He won eleven Academy Awards. |
| A．How Charlton Heston became famous. |
| B．How Charlton Heston began his career. |
| C．Who made Charlton Heston a popular star. |
| D．Who made Charlton Heston win so many awards. |
To be sure, only children experienced some things differently from those with sisters and brothers. Many feel more pressure to succeed. In the absence of brothers and sisters, only children also tend to look more exclusively to their parents as role models.
In India, 10-year-old Saviraj Sankpal founded a support group for the tiny minority of only children. Among other things, the group does volunteer work to counter the myth that they are not responsible. “People think we’re treated too kindly and ruined,” says Sankpal, a computer engineering student. “But I’d like to remind them how lonely it can get.”
Most only children, however, say they wish for sisters or brothers only when it comes to caring for aging, unhealthy parents. Britain’s David Emerson, coauthor of the book The Only Child, says that such a person bears a terrible burden in having to make all the decisions alone. Emerson knows from experience: After his father died, he chose to move his elderly mother from their family home, where she was vulnerable(易受攻击的) to house breakers, to a new one with more security. “The move was quite hard on her, and she might feel that I pushed her into it,” he says. “After all, I am left with that responsibility.”
In the future, more and more only children will likely face similar choices. With working mothers increasingly the rule, many families are finding they simply don’t have the time, money or energy to have more than one child. As only children become common, perhaps the world will realize that the charge made against them is unjust.
| A．critical | B．objective | C．hostile | D．unjust |
| A．find a support group for their only children |
| B．do volunteer work to help their only children |
| C．let their only children make all the decision alone |
| D．set good examples for their only children |
| A．is the only one who cares about her |
| B．doesn’t want to leave her alone |
| C．wants to share the responsibility with her |
| D．is worried about her safety |
| A．spend all her time and money on her only child |
| B．be responsible for bringing up her only child |
| C．have and bring up only one child |
| D．devote all her energy to her job |
Norah has a cottage on a cliff above a big bay. In winter it could be very nasty because of strong winds and sea spray. In fact, when a gale was blowing, Norah and her husband got used to sleeping in a small room downstairs, because their bedroom upstairs, which faced the gales, had a very big window, and they were afraid that an extra violent gust might break it and blow pieces of broken glass over them.
Also, the salt spray from the sea put an end to many of the colorful plants Norah planted in the garden. She tried putting up a fence to protect them, but the wind just hit it, went up over the top and then down the other side, so in the end she filled the garden with trees and bushes that liked salt.
But most of the summer Norah enjoyed her cottage and garden very much. At weekends she could sit out-of-doors in the sun, looking at the beautiful view, with interesting ships and boats passing by, and she could very easily cycle down to the sea for a swim.
Now, Norah and her husband had plenty of friends and relations. In the summer most of them used to come to enjoy the beautiful place, and in the end it really became quite annoying for Norah and her husband. When they were at home, they found friends and relations arriving, expecting to be given unlimited drinks and meals, and to sit in the sun for hours, talking as if Norah and her husband had nothing else to do but entertain and listen to them.
This went on for several years. Norah did not wish to appear rude by refusing to let her friends and relations in, but on the other hand, she was getting tired every summer.
Then one day Norah was complaining about this to her hairdresser while she was doing her hair. “You’re disturbed by too many uninvited guests, are you?” said the hairdresser. “Why don’t you try my way of escaping?”
“What’s that?” asked Norah.
“Well,” the hairdresser answered, “when the bell rings, I put on my coat and take my shopping bag. If it’s someone I don’t want to see, I say innocently, ‘I’m sorry, but I’ve got to go out. But…’”
| A．wastes produced by some birds living near the sea |
| B．great waves caused by strong wind |
| C．plants floating on the surface of the sea |
| D．very small drops of sea water sent through the air by something |
| A．a lot of friends came to visit them in winter |
| B．few friends came to visit them in winter. |
| C．Friends came to visit them only for drinks and meals |
| D．Norah was a good cook |
| A．A Good Place of Enjoying the Sea |
| B．A Warm-hearted Couple |
| C．A Clever Way of Escaping |
| D．A Visit to Norah |
| A．If I am tired, I say, ‘Sorry, can you come next time?’ |
| B．If it’s someone I like to see, I say, ‘How lucky! I’ve just come in!’ |
| C．If it’s someone I like to see, I say, ‘How happy to see you! I was going shopping, but now I’ve changed my mind.’ |
| D．If it is fine that day, I say, ‘I am tired, but I’ll show you around the place, anyhow.’ |
When Emily Beardmore first heard that a trip was being planned by the biology class at Windsor High School, she thought about how much fun it would be.
“I thought it would be a really good experience to go with other friends and teachers to another country in an environment other than a vacation environment,” the 10- year-old girl said.
A few months later, Emily got her chance when she and 14 of her classmates, along with biology teacher Tamara Pennington went to Costa Rica for eight days in late May.
“It was not just a tour,” said Pennington, who organized the trip. “You can go to any place in the world on just a tour. This one was practical, really working with the sea turtles and practicing conservation (保护). It just seemed like the perfect science field trip for kids who think they want to get into science to see what it’s really like to be out in the field and enjoy themselves.”
Emily said her time on the turtle project, which was the focus of the trip, was “crazy”. “We were walking on the beach at night and you can’t see anything — just see a big black dot (点),” she said with a laugh. “I was not expecting the turtles to be that big.” The turtles are leatherback turtles, which are becoming extinct because their eggs are used as food.
“When they would move their legs while laying their eggs they were really hard to control because they were a lot more powerful than you would imagine,” Emily said.
Once the eggs were collected, the students took them back to a hatchery (孵化场) and dug holes to copy the hole the mother turtle had made and then buried the eggs for the 60 days needed to hatch.
“It was an amazing experience,” Emily said. “You go to another country to see what their culture is like and learn what their everyday lives are like. It made me really want to help out my mom a lot more than I do, and value what I have.” What did Pennington consider the trip to be?
| A．It was a common tour to a foreign country. |
| B．It was a journey to practice what students learned. |
| C．It was a trip to do practical science activities. |
| D．It was to attract students’ interest in science. |
From what Emily said on her turtle project, we know that _____.
| A．she was afraid of walking on the beach at night |
| B．she didn’t dare to catch the powerful turtles |
| C．she got crazy at the sight of turtles at night |
| D．she had thought turtles were small animals |
Which of the following is NOT true according to the passage?
| A．Emily thought the trip being planned by the biology class would be fun. |
| B．Totally, 16 people went to Costa Rica for the 8-day trip in May. |
| C．Generally, it takes about 60 days to hatch little turtles. |
| D．The trip mainly aimed to get fun and rest. |
Amusement parks make most of their money from admission fees paid by guests attending the park. Other sources include parking fees, food and drink sales and souvenirs. Practically all amusement parks operate using one of two admission principles:
Pay-as-you-go In this form, a guest enters the park at little or no charge. The guest must then buy rides one by one, either at the attraction’s entrance or by buying ride tickets. The cost of the attraction is often based on its complexity (复杂性) or popularity. The park may allow guests to buy unlimited admissions to all attractions within the park. A pass is then shown at the attraction entrance to gain admission.
Disneyland opened in 1955 using the pay-as-you-go form. Initially, guests paid the ride admission fees at the attractions. Soon, the problems of dealing with so many coins led to the development of a ticket system that, while now out of use, is still part of the amusement-park vocabulary. In this new form, guests bought ticket books that contained a number of tickets, with “A,” “B” and “C.” Rides and attractions using an “A-ticket” were generally simple, with “B-tickets” and “C-tickets” used for the larger, more popular rides. Later, the “D-ticket” was added, then finally the now-famous “E-ticket,” which was used for the biggest rides, like Space Mountain. Smaller tickets could be traded up for use on larger rides. Disneyland, as well as the Magic Kingdom at Walt Disney World, gave up this practice in 1982.
The advantages include:
guests pay for only what they choose to experience
attraction costs can be changed easily
The disadvantages include:
guests may get tired of spending money almost continuously
guests may not spend as much on food or souvenirsWhat is the passage mainly about?
| A．Attractions of amusement parks |
| B．Admission fees of amusement parks. |
| C．Admission principles of amusement parks |
| D．Sources of income of amusement parks. |
According to the pay-as-you-go principle, guests _____.
| A．don’t pay at the gate of the park |
| B．must pay for each ride they take |
| C．have to pay for all rides in the park |
| D．needn’t pay after entering the park |
According to the passage, what is the meaning of the underlined word “Initially” in Paragraph 3?
| A．Gradually. | B．At the beginning. | C．At last. | D．Commonly. |
What would be introduced following the passage?
| A．The other admission principle |
| B．Amusement parks’ earnings. |
| C．Some other admission principles |
| D．Users of the pay-as-you-go principle. |