It’s never a real problem for us when the weather gets cold. We can put on more clothes, stay next to a fireplace, turn on the air conditioner or simply travel to a warmer city to spend the winter – people have many different ways of dealing with the cold.
But things are not as easy for plants. Unlike humans, plants can’t move to escape the cold or generate heat ( 发热) to keep themselves warm. So how do they manage to survive the freezing winter?
It turns out that plants have their own strategies （策略） too, said a study published on Dec 22 in the journal Nature.
According to researcher Amy Zanne of George Washington University, US, the cold is a big challenge for plants. Their living tissues （活组织） can be damaged when they freeze. “It’s like a plant’s equivalent to frostbite ( 相当于冻疮),” Zanne told Science Daily. Also, the process of freezing and thawing (解冻) can cause air bubbles （气泡） to form in the plant’s water transport system. “If enough of these air bubbles come together as water thaws they can block the flow of water from the roots to the leaves and kill the plant,” she explained.
To live through cold weather, plants have developed three traits （特性） , according to the study. Some plants, such as oak trees（橡树）, avoid freezing damage by dropping their leaves before the winter chill sets in – effectively shutting off the flow of water between roots and leaves – and growing new leaves and water transport cells when the warm spring returns.
Other plants, pine trees（松树） for example, protect themselves by narrowing their water transport cells, which makes it easier for cells to travel among air bubbles.
The third strategy is also the most extreme – some plants die on the ground in winter and start growing as new plants from seeds when conditions get warmer.
However, the study also found that these smart strategies were developed very slowly – over millions
of years of evolution （ 进化）. This leads scientists to worry that plants may not be able to deal with human-caused climate change, which has only started occurring over the past few decades.
Scientists are hoping that this study can help people find possible ways to save plants from the threat
of climate change.
What is the article mainly about?
| A．Why plants are not afraid of the winter chill. |
| B．The ways that plants survive cold weather. |
| C．Changes in plants’ water transport system in winter. |
| D．How plants evolve to keep up with climate change. |
According to the article, if a plant freezes in the winter, ______.
| A．it produces more living tissues to stay alive |
| B．its leaves quickly fall out and its roots begin to die |
| C．lots of air bubbles form in its water transport system |
| D．its water transport system could be blocked in the spring |
What are scientists worried about when it comes to plants according to the article?
| A．Plants may not be able to adapt to the increasingly cold climate. |
| B．Human activities might have a great impact on the pace of plants’ evolution. |
| C．Plants may not be able to evolve fast enough to adapt to human-caused climate change. |
| D．The strategies plants develop are not good enough to protect them against cold. |
根据短文内容，从下框A~F选项中选出能概括每段主题的最佳选项。选项中有一项为多余项。
| A. A sense of humour is not an inborn ability. B. A sense of humour can be developed in our life. C. A sense of humour helps us from several aspects. D. A sense of humour means more than telling jokes. E. A sense of humour can be expressed in many ways. F. A sense of humour helps people to better enjoy life. |
As awareness of the benefits of humour increases, most of us want to get all the laughs we can. It seems that almost every day there is another new discovery about the power of humour to help us physically, mentally, emotionally, and spiritually. Every system of the body responds to laughter in some important or positive way.
Many people mistakenly believe that we are born with a sense of humour. They think that when it comes to a sense of humour. “Either you have got it or you don’t.” This is
false! What is true, however, is that the ability to laugh and smile is actually something we are born with. For example, we laugh when we are tickled under the arm, even without thinking about how to react.The parts of the brain and central nervous system that control laughing and smiling are mature at birth in human infants, but that is not the same thing as having a sense of humour. (After all, when a baby laughs in his small bed we don’t rush over and say, “That kid has a great sense of humour!”) Your sense of humour is something you can develop over a lifetime. Don’t be nervous before others and try to laugh at yourself-then you will make them laugh too.
Humour includes a lot more than laughing and joke telling. Many people worry needlessly that they do not have a good sense of humour because they are not good joke tellers. More than jokes, a sense of humour requires being willing and able to see the funny side of life’s situations as they happen. In fact, one of the best definitions（定义）of a sense of humour is “the ability to see the nonserious element in a situation.”
There may be a thousand different ways to express your sense of humour, but joke telling is only one of those ways. As more is discovered about how humour benefits our life, more people will be able to see and enjoy the humour when they are in a difficult situation. Life depends on air, food and water, but it is made easier to live with a good sense of humour.
GU Zhaodi, 60, had taken water for granted for years. In fact, no one in the beautiful lake city of Wuxi, Jiangsu Province had bothered to spare a thought on water.
But all that changed dramatically overnight last month when taps in the city ran dry. Due to a blue-green algae(藻类) outbreak in Taihu Lake, China’s third largest freshwater lake and the source of drinking water for 4 million Wuxi residents(居民),water from the city’s taps became dark and smelly.
“I can’t believe there is no water for drinking, let alone cooking and washing,”said Ｇu.
The lake was blanketed with the algae, giving off a strong smell of rotting meat. A stone thrown into it took a long time to sink. Experts said that algae usually boom because of hot water and rich chemicals like phosphor(磷)in the water.
“High temperature and a lack of rain in the past few months helped the growth of algae,”said Zhang Lijun, an official from the State Environment Protection Administration. “However, pollution from human activity should be most blamed for the disaster.”
Taihu Lake is surrounded by many small factories, whichsprang up in the 1980s.Inthe 1990s,many foreign-funded(外资的) companies joined in. The industries prospered(繁荣)，Wuxi has grown into one of the wealthiest cities in East China.
But that came at the price of pollution. The lake was treated like a waste dump(垃圾堆)，with factories emptying industrial waste and untreated sewage(污水)into it.
Although, after the government's effort, life in the city has gone back to normal, the one-week crisis（危机）rang a bell for the government and local people.“It's time to rebuild the beauty of nature, or our lives will be at risk,”said Gu.
“A safe environment comes first. Economic growth will be nothing without fresh water to drink and clean air to breathe.” said China Daily.The following can not help the blue green algae grow______
| A．high water temperature | B．rich chemicals in the water |
| C．a lack of rain | D．plentiful water and sunshine |
What can we learn from the passage?
| A．The one-week disaster has made the local people realize the importance of building a beautiful city. |
| B．It is human activity rather than the algae that is to blame for the water pollution. |
| C．Only when the environment is safe and friendly can man live a better and healthier life. |
| D．Environment should be taken into consideration first if a city plans to develop its economic. |
According to the passage ,Taihu Lake________
| A．is the third largest lake in China. |
| B．is surrounded by many foreign-funded factories and companies. |
| C．used to be a waste dump. |
| D．suffered from industrial waste，untreated sewage and algae. |
The underlined phrase “sprang up” in the sixth paragraph means______
| A．develop quickly | B．produce goods quickly |
| C．come to life | D．grow up |
When a rather dirty, poorly dressed person kneels at your feet and puts out his hands to beg for a few coins, do you hurry on, not knowing what to do, or do you feel sad and hurriedly hand over some money? What should our attitude to beggars be? There can be no question that the world is full of terribly sad stories. It must be terrible to have no idea where our next meal is going to come from. It seems cruel not to give some money to beggars.
Certainly, most of the world’s great religions (宗教) order us to be open-hearted and share what we have with those less fortunate than ourselves. But has the world changed? Maybe what was morally (道德方面) right in the old days, when one knew exactly who in the village had suffered misfortune and needed help, is no longer the best idea. Quite a few people will not give to beggars. Let us look at their arguments.
First, some believe that many city beggars dress up on purpose to look pitiable and actually make a good living from begging. Giving to beggars only encourages this sort of evil (恶行). Secondly, there is the worry that the money you give will be spent on beer, wine or drugs. Thirdly, there is the opinion that there is no real excuse for begging. One might be poor, but that is no reason for losing one’s sense of pride and self-dependence.
Related to this is the opinion that the problem should be dealt with by the government rather than ordinary people. Some people think beggars should go to the local government department and receive help.
It is hard to come to any final conclusion; there are various cases and we must deal with them differently. A few coins can save a life in some situations, and even if the money is wasted, that does not take sway the moral goodness of the giver.What is mainly discussed in the passage?
| A．Moral deeds of people. |
| B．Religious activities of the church. |
| C．Moral goodness of the giver. |
| D．Arguments on giving to beggars. |
What can we infer from the sentence “But has the world changed?” in the second paragraph?
| A．People no longer know who suffers misfortune in the village. |
| B．Some people will not do what was morally right in the past. |
| C．We don’t meet with those who need help any more. |
| D．Now it is the government’s duty to help the beggars. |
Which of the following is NOT mentioned in the passage?
| A．Some people dress up to pretend to be beggars. |
| B．Some beggars want money to help their children go to school. |
| C．Some beggars use the money to buy drugs. |
| D．Some beggars have no excuse for begging. |
In the last paragraph, the writer thinks that it is hard to come to any final conclusion, because .
| A．the cases can be so different |
| B．there are so many beggars |
| C．there is so much money wasted |
| D．there are so many different arguments |
Every day we go to school and listen to teachers, and the teacher will ask us some questions. Sometimes, the classmates will ask your opinions of the work of the class. When you are telling others in the class what you have found out about these topics, remember that they must be able to hear what you are saying. You are not taking part in a family conversation or having a chat with friends --- you are in a situation where a large group of people will remain silent, waiting to hear what you have to say. You must speak so that they can hear you loudly enough and clearly enough but without trying to shout or appearing to force yourself.
Remember, too, that it is the same if you are called to an interview whether it is with a professor of your school or a government official who might meet you. The person you are seeing will try to put you at your ease in ordinary conversation but the situation is somewhat different from that of an ordinary conversation. You must take special care that you can be heard.When you speak to the class, you should speak __________.
| A．as loudly as possible | B．in a low voice | C．loudly | D．forcefully |
The situation in the class is _________ that in your house.
| A．not very different from | B．sometimes the same as |
| C．sometimes not the same as | D．not the same as |
If you are having a conversation with an official, the most important thing for you is _____________.
| A．to show your ability | B．to be very gentle |
| C．to make sure that you can be heard | D．to put the official at ease |
The main idea of this passage is __________.
| A．that we must use different ways at different situations |
| B．that we must speak loudly |
| C．that we must keep silent at any time |
| D．that we must talk with the class |
The most frightening words in the English language are “our computer is down.” You hear it more and more when you are on business. The other day I was at the airport waiting for a ticket to Washington and the girl in the ticket office said, “I’m sorry, I can’t sell you a ticket. Our computer is down.”
“If your computer is down, just write me out a ticket.”
“I can’t write you out a ticket. The computer is the only one allowed to do so.” I looked down at the counter and every passenger was just standing there drinking coffee and staring at the black screen. Then I asked her, “What do you do?”
“We give the computer the information about your trip, and then it tells us whether you can fly with us or not.”
“So when it goes down, you go down with it.”
“That’s right, sir.”
“How long will the computer be down?” I wanted to know.
“I have no idea. Sometimes it’s down for 10 minutes, sometimes for two hours. There is no way we can find out without asking the computer, and since it’s down, it won’t answer us.”
After the girl told me they had no backup computer, I said, “Let’s forget the computer. What about your planes? They are still flying, aren’t they?”
“I can’t tell without asking the computer.”
“Maybe I could just go to the gate and ask the pilot if he’s flying to Washington.” I suggested.
“I wouldn’t know what gate to send you to. Even if the pilot was going to Washington, he couldn’t take you if you didn’t have a ticket.”
“Is there any other airline flying to Washington within the next few hours?”
“I wouldn’t know,” she said, pointing at the desk screen. “Only IT knows. It can’t tell me.”
By this time there were quite a few people standing in line. The words soon spread to other travelers that the computer was down. Some people went, some people started to cry and still others kicked their luggage.The word “down” in the sentence ‘Our computer is down.’ means _____________.
| A．falling | B．downcast | C．drop | D．dead |
The best title of the article is _________.
| A．Asking the Computer |
| B．The Computer of the Airport |
| C．The Most Frightening Words |
| D．When the Computer Is Down |
What could the girl in the ticket office do for the passengers without asking the computer?
| A．She could answer the passengers’ questions |
| B．She could do nothing. |
| C．She could sell a ticket. |
| D．She could write out a ticket. |