Scientists have identified the order of the gene of the giraffe for the first time to help explain how the tallest animals on earth developed their remarkably long necks.
Being a giraffe is not easy. To pump blood two meters up from the chest to the brain calls for a powerful heart and twice the blood pressure of other mammals. Giraffes also need special safety system to let them bend down for a drink and raise their heads again without feeling Dizzy.
The animals* unique body structure has long been a puzzle for biologists, including Charles Darwin. Now, by comparing the gene of the giraffe with its closest relative, the short-necked okapi, scientists have solved part of the puzzle by studying changes in a small number of genes responsible both for regulating body shape and circulation. This suggests that the development of a long neck and a powerful heart went hand in hand, driven by a relatively small number of genetic changes.
The interpretation of the genetic factors behind the giraffe's remarkable heart system could also be instructive for human health, since the animals appear to avoid the kind of organ damage often found in people with high blood pressure.
The more fundamental question of why giraffes developed their long necks remains open, however. The apparently self-evident idea that it was to reach ever-higher food supplies has been challenged in the past 20 years by a competing belief that it is actually due to competition among fighting males for females.
Unlike long-necked birds, which have additional vertebrae (椎骨)，giraffes have the same seven vertebrae found in all mammals, although theirs are greatly extended.
1.A strong heart is very important for a giraffe because it .
A. keeps the giraffe safe in different environments.
B. pumps blood to the brain high above its body.
C. helps the giraffe find a drink at lower places.
D. keeps the blood pressure at a normal level.
2.Scientists compare the gene of the giraffe and the short-necked okapi because the latter .
A. has a quite special body structure. B. has gone through few genetic changes.
C. is a puzzle worth further study. D. is in the same family as the giraffe.
3.Which possibly caused the giraffe to develop a long neck?
A. Its attempts to attract females. B. Its favorite food at high places.
C. Its need to avoid organ damage. D. Its greatly-extended vertebrae.
4.What’s the author’s purpose of writing this passage?
A. To describe giraffes body structure. B. To explain genetic changes in animals.
C. To introduce a new finding of science. D. To challenge a belief of twenty years.
When people argue about whether coffee is good for health, they’re usually thinking of the health of the coffee drinker. Is it good for your heart? Does it increase blood pressure?
Does it help you concentrate? However, coffee affects the health of the human population in other ways, too.
Traditionally, coffee bushes are planted under the canopy (树荫）of taller trees. However， more and more fanners in Latin America are deforesting the land to grow full-sun coffee. At first, this increases production because more coffee bushes can be planted if there aren5t any trees. With increased production come increased profits.
Unfortunately, deforesting for coffee production immediately decreases the local wildlife habitat, because native birds nest and hide from predators(捕食者）on the tall trees and migrating birds rest there.
Furthermore, in the long term, the full-sun method also damages the ecosystem because more chemical fertilizers and pesticides(杀虫剂)are needed to grow the coffee. The fertilizers and pesticides kill insects that eat coffee plants, and then the birds eat the poisoned insects and also die. The chemicals kill or sicken other animals as well, and can even enter the water that people will eventually drink.
Fortunately, farmers in Central and South America are beginning to grow more coffee bushes in the shade. We can support these farmers by buying coffee with such labels as “shade-grown” and ‘"bird-friendly”. Sure, these varieties might cost a little more. But we’re paying for the health of the birds, the land, ourselves, and the planet. I think it’s worth it.
1.How do farmers get more land to grow full-sun coffee?
A. They move to other countries.
B. They cut down trees.
C. They turn grassland into farmland.
D. They buy more land from other farmers.
2.Compared with the traditional method, what advantage does the full-sun method have?
A. It can increase the production of coffee. B. It can promote peopled health.
C. It can provide more nests for birds. D. It can protect the ecosystem.
3.Which opinion does the author agree with?
A. People should buy full-sun coffee.
B. Farmers should change the places to grow coffee.
C. Shade-grown coffee should be supported.
D. Pesticides should be forbidden in coffee planting.
4.What can we learn from the passage?
A. It is quite worthwhile to buy shade-grown coffee at any cost.
B. Farmers all have realized the importance of protecting the environment now.
C. The full-sun method does good to the health of human beings in the long run.
D. South American farmers are taking action to plant coffee bushes in the traditional way.
Aerial (空中的）performer Jennifer Bricker was born without legs, but she never let it stop her.
Wrapped in a loop (圈）of red silk hung from the ceiling, Jennifer Bricker climbs and twists to the music. Her head hangs down and her strong arms let go as she balances on her back, high above the ground — a move that is all the more daring because she has no legs.
Jennifer was a few months old when she was adopted by Sharon and Gerald Bricker. She had big brown eyes, a bright smile, and huge amounts of energy. When a doctor advised her adoptive parents to carry her around in a kind of bucket (桶)，they refused.
Jennifer soon learned to walk and run on her hands and bottom, and grew up fearlessly climbing trees and bouncing on the trampoline (蹦床）with her three older brothers.“My parents didn’t treat me differently so I didn’t grasp the concept that I was different .1 knew I didn't have legs but that wasn’t stopping me from doing the things I wanted to do.”
At the age of three she was fitted with artificial legs, but she never really took to them she moved more freely without them.
In 1996 the Olympic Games took place in Atlanta. Jennifer loved to watch the women's gymnastics team, and especially adored the 14-year-old Dominique Moceanu who competed for the US. When Moceanu and the women’s team won the gold, Jennifer decided she was going to be a gymnast, too. She took up power tumbling, which involves performing floor exercises down a runway. But Jennifer did not want any allowances to be made for her disability.
At the age of 10 she took part in the Junior Olympics and by age 11 she was the tumbling champion for the state of Illinois.
Jennifer now travels the world as an inspirational speaker and acts as an aerial performer.
1.What do we know about Jennifer Bricker?
A. She felt embarrassed without legs.
B. She was carried in a bucket as a baby.
C. She was brought up as a normal child.
D. She lost her legs when she was adopted.
2.Why did Jennifer determine to be a gymnast?
A. Because she knew that she was different from others.
B. Because she was greatly influenced by Dominique Moceanu.
C. Because she was eager to participate in the Junior Olympics.
D. Because she wanted to make allowances for her disability.
3.Which of the following can best describe Jennifer Bricker?
A. Clever. B. Cautious. C. Sensitive. D. Self-respecting.
4.What is the passage mainly about?
A. The growing process of a disabled person.
B. The memory of an aerial performer.
C. The experiences of an adoptive family.
D. The sufferings of a gymnast.
The experience of life can show one’s “determination”. Complex challenges early in life helped the following people develop skills that got them to the top of their professions.
Sean Combs, CEO, Sean John
Combs began a generation of hip-hop talent and made a lasting influence on fashion. But his story could have turned out much differently: His drug dealer father was killed when he was 3. “It made me work even harder.” he recently said.
Howard Schultz, Executive Chairman, Starbucks Schultz grew up in public housing in Brooklyn, surrounded by poverty, and was the first in his family to go to college (on a football scholarship).After training in sales, he set up the company that would later buy Starbucks. In the course of the year I spent trying to raise money，Ispoketo242people,and217ofthemsaidno.’’hesaid.
Ursula Burns, Chairwoman, VEON; Former CEO, Xerox
Her family was so poor that her single mother traded office cleaning for health care. But Bums’ early gift for maths won her a scholarship and an internship at Xerox，where she would compete her way to the top. ‘‘ I’m a black lady from the Lower East Side,” she says, S6Not a lot scares me.”
Geisha Williams, CEO, PG&E
Her parents fled Cuba when Williams was 5. By 7, she was her parents, main translator in talks with lawyers and accountants at grocery stores they owned. The experience did help her. I went from thinking I could be a manager to thinking I could do something much bigger.55 she told Fortune.
1.How did the death of Combs5 father influence him?
A. It made him even stronger. B. He became a drug dealer.
C. It made him a failure. D. He became a hip-hopper.
2.Who did best in math at school?
A. Combs B. Williams C. Burns D. Schultz
3.What can we learn from the passage?
A. Cuba is a good place to do business.
B. Difficulty in life pushed Williams forward.
C. No one wanted to help Schultz at first.
D. Poor family kids can be successful easily.
听下面一段独白，回答以下小题。
1.What does the speaker think of his mother's performance?
A. Amazing. B. Dangerous. C. Just-so-so.
2.How old is the speaker's brother?
A. 6. B. 11. C. 14.
3.Why can the speaker’s father do a good job according to the speaker?
A. He can dance well.
B. He has a loud voice.
C. He has a good sense of balance.
4.What animal does the speaker's family have?
A. A horse. B. A dog. C. A rabbit.
听下面一段较长对话，回答以下小题。
1.What does the man think of the woman's father's idea?
A. Reasonable. B. Interesting. C. Unbelievable.
2.What did the woman have to do at mealtimes?
A. Sit silently. B. Speak French. C. Put her hands on the table.
3.What does the woman think was a good thing at school?
A. Learning manners. B. Studying by herself. C. Going to church before class.
