A rainforest is an area covered by tall trees with the total high rainfall spreading quite equally through the year and the temperature rarely dipping below l6℃. Rainforests have a great effect on the world environment because they can take in heat from the sun and adjust the climate. Without the forest cover，these areas would reflect more heat into the atmosphere，warming the rest of the world. Losing the rainforests may also influence wind and rainfall patterns，potentially causing certain natural disasters all over the world.
In the past hundred years，humans have begun destroying rainforests in search of three major resources（资源）：land for crops，wood for paper and other products，land for raising farm animals. This action affects the environment as a whole. For example，a lot of carbon dioxide（二氧化碳）in the air comes from burning the rainforests. People obviously have a need for the resources we gain from cutting trees but we will suffer much more than we will benefit.There are two main reasons for this. Firstly，when people cut down trees，generally they can only use the land for a year or two. Secondly，cutting large sections of rainforests may provide a good supply of wood right now，but in the long run it actually reduces the world's wood supply.
Rainforests are often called the world's drug store. More than 25％ of the medicines we use today come from plants in rainforests. However，fewer than l％of rainforest plants have been examined for their medical value. It is extremely likely that our best chance to cure diseases lies somewhere in the world's shrinking rainforests.
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Rainforests can help to adjust the climate because they
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What does the word "this" underlined in the third paragraph refer to?
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It can be inferred from the text that
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What might be the best title for the text?
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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 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 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.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 |
It can be inferred from the passage that ________.
| A．nowadays people who want to change their skin colour 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 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 gen for melanosome 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．indifferent |
When the musical sound rings you, you immediately reach for your pocket ready to have a chat. But although you probably use it all the time, have you ever stopped to think about the manners related to talking on the phone? If you haven’t, here are some tips to guide you.
●Always give the person you are calling plenty of time to get to the phone before you hang up. If the person who answers is not the one you want，give your name and ask if you may speak to the person you want.
●Think about the time you call people. Try not to call too early in the morning(before about 9:00)or too late at night(after about 9:30). Also try not to call at mealtimes.
●If you go by plane to visit your relatives at Christmas, remember to follow airline instructions. Cell phones must be turned off as soon as the plane doors are closed and remain so until the doors open again on arrival.
●When face to face with someone, do not talk on the phone. It is rude to be on the phone when a waiter is trying to take your order in a restaurant, or when you are returning the shoes you have just been trying on in a shop. Finish any face-to-face business before taking a call. Continuing to use the phone while nodding to the person in front of you is quite impolite.
●When in a restaurant with your friends，keep phone conversations short. Make a call only if it is important. Practise speaking in a low voice. If no one looks your way, you’ve got it.
●If you go to a theatre, a concert or a cinema, consider the other people around you. Check that your phone is “off” before you enter. If you are expecting a very important call, put your phone on “vibrate”(振动)and run for the exit as soon as you feel it. If you forget both “off” and “vibrate” and your phone rings, don’t answer it, turn it off straight away.Which is true according to the passage above?
| A．You may call people anytime as you like. |
| B．You may talk loudly on the phone at dinner in the restaurant. |
| C．You may keep on talking on the phone while greeting somebody. |
| D．You may call people as soon as you get on the plane，but not after the doors are closed. |
We may infer from these tips that__________.
| A．some people don’t pay much attention to manners while making cell phone calls |
| B．you may ask to leave a message unless the person you are calling is in |
| C．calling people too early or too late in the morning is not polite |
| D．almost everyone has got a cell phone |
What does the underlined sentence “…you’ve got it” mean in the passage?
| A．You have succeeded in making a call without disturbing others. | |
| B．You have made the phone call brief and interesting. | |
| C．You’ve got the message you are waiting for. | D．You have made a phone call secretly． |
From the tips given above, we can decide the writer is sure to share the opinion that______.
| A．1ike the saying “clothes make a man”, nowadays cell phones make a man | |
| B．as the old saying goes, money talks; nowadays cell phones talk | |
| C．the way we use the cell phones tells what we are like | D．we are what cell phones we use |
Like a growing number of young women in Vietnam’s northern part city of Haiphong, Pham Thi Hue was infected with HIV by her husband, one of the town’s many drug users. But instead of being shamed into silence, as Vietnamese with HIV and AIDS are, the 25-year-old tailor and mother of one went public, appearing on television and at conferences. Her business suffered and her neighbors insulted (辱骂)her, but Hue has now become the public face of Mothers and Wives, an HIV/ AIDS support group established in Haiphong by a Norwegian nongovernmental organization and her neighborhood’s People’s Committee. Last year, she founded a smaller group named after a local flower. People who need advice on treatment or help preparing bodies for burial can dial a hot line and get assistance from able and sympathetic(同情的)HIV victims. “We gather to support each other,” Hue says. “When we are sick, what we need most is encouragement and comfort from people who understand our situation and are willing to share our happiness, as well as our sadness.”
On a hot and damp night last month, Hue welcomed into her small home a very thin woman, also a tailor, who was HIV positive. The woman tearfully told Hue that she had not told anyone about her condition, fearing that she would lose customers and that her daughter would be insulted at school. Hue became the wise elder, offering medical and personal advice. What did Pham Thi Hue do after she was infected with HIV?
| A．She kept silent | B．She worked as usual |
| C．She stayed at home and cried every day. | D．She went public and gave help to others. |
It can be inferred from the passage that the group Pham Thi Hue founded is made up of____.
| A．drug users | B．HIV victims | C．all kinds of patients | D．poor people |
From the passage we can learn that Pham Thi Hue is a woman who is_______.
| A．weak and kind | B．foolish and idle | C．brave and helpful | D．cautious and energetic |
GUATEMALA CITY （Reuters） – A fish that lives in mangrove swamps(红树沼泽) across the Americas can live out of water for months at a time, similar to how animals adapted(适应) to land millions of years ago, a new study shows.
The Magrove Rivulus, a type of small killifish, lives in small pools of water in a certain type of empty nut or even old beer cans in the mangrove swamps of Belize, the United States and Brazil. When their living place dries up, they live on the land in logs(圆木), said Scott Taylor, a researcher at the Brevard Endangered Lands Program in Florida.
The fish, whose scientific name
is Rivulus marmoratus, can grow as large as three inches. They group together in logs and breathe air through their skin until they can find water again.
The new scientific discovery came after a trip to Belize.
“We kicked over a log and the fish just came crowding out,” Taylor told Reuters in neighboring Guatgemala by telephone. He said he will make his study on the fish known to the public in an American magazine early next year.
In lab tests, Taylor said he found the fish can live up to 66 days out of water without eating.
Some other fish can live out of water for a short period of time. The walking catfish found in Southeast Asia can stay on land for hours at time, while lungfish found in Australia, Africa and South America can live out of water, but only in an inactive state. But no other known fish can be out of water as long as the Mangrove Rivulus and remain active, according to Patricia Wright, a biologist at Canada’s University of Guelph.
Further studies of the fish may tell how animals changed over time.
“These animals live in conditions similar to those that existed millions of years ago, when animals began making the transition(过渡) from water onto land,” Wright said.
1. The Mangrove Rivulus is a type of fish that _______.
A. likes eating nuts
B. prefers living in dry places
C. is the longest living fish on earth
D. can stay alive for two months out of water
2. Who will write up a report on Mangrove Rivulus?
A. Patricia Wright.
B. Scott Taylor.
C. Scientists from Belize.
D. Researchers in Guatemala.
3. According to the text, lungfish can ________.
A. breathe through its skin
B. move freely on dry land
C. remain alive out of water
D. be as active on land as in water
4. What can we say about the discovery of Mangrove Rivulus?
A. It was made quite by accident.
B. It was helped by Patricia Wright.
C. It was based on a lab test of sea life.
D. It was supported by an American magazine.
Most young people enjoy some form of physical activity. It may be walking, cycling or swimming, winter skating or skiing in winter. It may be a game of some kind, football, hockey, golf or tennis. It may be mountaineering（爬山）.
Those who have a passion（热情）for climbing high and difficult mountains are often looked upon with astonishment. Why are men and women willing to suffer cold and hardship, and to take risks on high mountains? This astonishment is caused probably by the difference between mountaineering and other forms of activity to which men give their leisure.
Mountaineering is a sport and not a game. There are no man-made rules, as there are for such games as golf and football. There are, of course, rules of a different thing that it would be dangerous to ignore（忽视），but it is this freedom from man-made rules that makes mountaineering attractive to many people. Those who climb mountains are free to use their own methods.
If we compare mountaineering and other more familiar sports, we might think that one big difference is that mountaineering is not a “team game”. We should be mistaken in this. There are, it is true, no“matches”between“teams”of climbers, but when climbers are on a rock face linked by a rope on which their lives may depend, there is obviously teamwork.
The mountain climber knows that he may have to fight forces that are stronger and more powerful than men. He has to fight the forces of nature. His sport requires high mental and physical qualities
A mountain climber continues to improve in skill year after year. A skier is probably past his best by the age of thirty, and most international tennis champions are in their early twenties. But it is not unusual for a man of fifty or sixty to climb the highest mountains in the Alps. They may take more time than younger men, but they probably climb with more skill and less waste of efforts and they certainly experience equal enjoyment.Mountaineering involves.
| A．cold | B．hardship | C．physical risk | D．all of the above |
The difference between a sport and a game has something to do with the kind of .
| A．activity | B．rules | C．uniform | D．participants |
Mountaineering can be called a team sport because.
| A．it is an Olympic event |
| B．teams compete against each other |
| C．mountaineers depend on each other while climbing |
| D．there are 5 climbers on each team. |
Which is the best title for the passage?
A．Mountaineering Is Different from Golf and Football k  |
| B．Mountaineering Is More Attractive than Other Sports |
| C．Mountaineering |
| D．Mountain Climbers |