Recently, some concerns have been raised about the health of the world's banana plants. Many media reports have said that bananas may completely disappear in the coming ten years.

Bananas are one of the world's most important food crops. They are also the fourth most valuable export. Bananas do not grow from seeds. Instead, they grow from existing plants. Bananas are threatened by disease because all the plants on a farm are copies of each other. They all share the same genetic weaknesses.

For example, the Cavendish banana is most popular in American markets. It is an important export crop. However, some kinds of fungus (真菌) organisms easily infect the Cavendish. Black Sigatoka disease affects the leaves of Cavendish banana plants. The disease is controlled on large farms by putting chemicals on the plant's leaves. Farmers put anti-fungal chemicals on their crops up to once a week.

Another fungal disease is more serious. Panama disease attacks the roots of the banana plant. There is no chemical treatment for this disease. Infected plants must be destroyed. Panama disease has affected crops in Southeast Asia, Australia and South Africa. There is concern that it may spread to bananas grown in the Americas. This could threaten an important export product for Central and South America.

The International Network for the Improvement of Banana and Plantain, whose headquarter lies in France, supports research on bananas. The group says that more research must be done to develop improved kinds of bananas.

The group says that fungal diseases mainly affect only one kind of banana. In fact, there are five-hundred different kinds of bananas. The United Nations Food and Agriculture Organization says the Cavendish banana represents only ten percent of world production.

The UN agency says farmers should grow different kinds of bananas. This protects against diseases that affect only one kind. Experts warn that disease may cause the Cavendish banana to disappear. This has already happened to one popular banana because of its genetic weakness against disease. (words: 335)

1.What does the passage mainly tell us?

A．Bananas are the world’s most important food crops.

B．There are five hundred different kinds of bananas.

C．The risk to a popular banana shows need to grow other kinds.

D．How to grow bananas in different countries.

2.Bananas are threatened by diseases because ___­­­­­­_______.

A．they have genetic weaknesses against disease.

B．they are one of the most valuable exports.

C．the only way to prevent it is to put chemicals on their leaves.

D．they grow from the seed

3.Panama disease__________.

A．doesn’t belong to fungal disease.

B．has spread to bananas in the world.

C．affects the leaves of banana plants.

D．destroys the bananas more seriously than Black Sigatoka disease.

4.We can infer from Paragraph 6 that ____________.

A．the center of the group is in the US.

B．the key to solving the disease is to research all kinds of bananas.

C．the Cavendish banana covers only a small part of the output of bananas.

D．each fungal disease affects five hundred different kinds of bananas.

5.According to the passage, which information is right?

A．The Cavendish banana can be mainly imported from North America and Europe.

B．Fungal diseases mainly affect the Cavendish banana.

C．The Cavendish banana won’t die out in the future.

D．Panama disease affects the leaves of banana plants.

People who multitask all the time may be the worst at doing two things at once, a new research suggests. The findings, based on performances and self-evaluation by about 275 college students, indicate that many people multitask not out of a desire to increase productivity, but because they are easily distracted and can’t focus on one activity. And “those people turn out to be the worst at handling different things,” said David Sanbonmatsu, a psychologist at the University of Utah.

Sanbonmatsu and his colleagues gave the students a set of tests and asked them to report how often they multitasked, how good they thought they were at it, and how sensation-seeking (寻求刺激) or imperative (冲动) they were. They then evaluated the participants’ multitasking ability with a tricky mental task that required the students to do simple mathematical calculations while remembering a set of letters.

Not surprisingly, the scientists said, most people thought they were better than average at multitasking, and those who thought they were better at it were more likely to report using a cellphone while driving or viewing multiple kinds of media at once. But those who frequently deal with many things at the same time were found to perform the worst at the actual multitasking test. They also were more likely to admit to sensation-seeking and impulsive behavior, which connects with how easily people get bored and distracted.

“People multitask not because it’s going to lead to greater productivity, but because they’re distractible, and they get sucked into things that are not as important.” Sanbonmatsu said.

Adam Gazzaley, a researcher at the University of California, San Francisco, who was not a member of the research group, said one limitation of the study was that it couldn’t find out whether people who start out less focused tend toward multitasking or whether people’s recognizing and understanding abilities change as a result of multitasking.

The findings do suggest, however, why the sensation-seeker who multitask the most may enjoy risky distracted driving. “People who are multitasking are generally less sensitive to risky situations.” said Paul Atchley, another researcher not in the group. “This may partly explain why people go in for these situations even though they’re dangerous.”

1.The research led by Sanbonmatsu indicates that people who multitask __________.

A. seek high productivity constantly

B. prefer handling different things when getting bored

C. are more focused when doing many things at a time

D. have the poorest results in doing various things at the same time

2.When Sanbonmatsu and his colleagues conducted their research, they __________.

A. assessed the multitasking ability of the students

B. evaluated the academic achievements of the students

C. analyzed the effects of the participants’ tricky mental tasks

D. measured the changes of the students’ understanding ability

3.According to Sanbonmatsu, people multitask because of their __________.

A. limited power in calculation

B. interests in doing things differently

C. inability to concentrate on one task

D. impulsive desire to try new things

4.From the last paragraph, we can learn that multitaskers usually __________.

A. drive very skillfully

B. go in for different tasks

C. fail to react quickly to potential dangers

D. refuse to explain the reasons for their behavior

When he thought of the past, my grandfather would sometimes show us photographs of himself at school．They were brown and faded, and it was hard to believe that the blurred figure of the little boy in the short trousers and socks could ever have been Grandfather．Besides, he wore a cap—and the boys in the photographs wore caps pulled so far forward that half of their faces were obscured．When Grandfather asked us to pick him out from the group, we would surely point to the wrong boy．

On one such occasion my younger sister, aged six, burst into tears when Grandfather proudly guided her finger to the right boy．"How could that boy be you?" she cried．"He should have a beard．” We were, of course, all convinced that grandfathers should have beards , preferably white and bushy, like our own grandfather's．

"I was a good scholar ,”Grandfather would say, wagging his beard over the photographs．" I should have been top of the c1ass if I hadn't had to get up at six every morning to milk the cows and chop the wood, and again when I came home from school．”

"But Saturdays? What did you do on Saturdays?"

"Saturdays, if it was fine, I’d be out all day in the fields with the men," replied Grandfather．"And if it was wet, I’d be helping my mother with odd jobs round the house．There wasn't much time for studying．"

We all tried hard to imagine what it would have been like to have been Grandfather getting up at crack of dawn and never, obviously, having a moment for himself．It seemed we had learnt something from what Grandfather had said about his childhood．

1．In the first paragraph of this passage, what the author really tells us is that______．

       A ．his grandfather used to wear short trousers, socks and a cap as well

       B．it was difficult to tell which of the boys in the photographs was Grandfather

       C．he didn't believe Grandfather wore a cap pulled forward when he was at school

       D．it was fun to watch boys in the photographs wearing caps pulled forward

2．The author's sister burst into tears because______________．       

       A．she did not get a chance to pick out Grandfather in the photographs

       B．she was told which was the right boy before she herself could pick him out

       C．other children did not agree with her that Grandfather should have had a beard

       D．she found Grandfather in the photographs did not have a beard

3．When Grandfather said, "I should have been top of the class…．", he meant____________．

       A if he had had more time for studying, he would have been the best in his class

       B．he should have spent more time studying rather than playing ball games

       C．his school days should not have been so hard and miserable

       D．he could have never been the best student even if he had studied still harder

4．In the last paragraph the author said, "We all tried hard to imagine…"because__________．

       A．the figures of the boys in the photographs were small and blurred

       B．the children had never experienced life like that of Grandfather

       C．the photographs Grandfather showed them were brown and faded

       D．Grandfather failed to tell them about his childhood in detail

Reading to dogs is an unusual way to help children improve their literacy skills （读写能力）With their shining brown eyes, wagging tails, and unconditional love, dogs can provide the nonjudgmental listeners needed for a beginning reader to gain confidence （自信心） , according to Intermountain Therapy Animals (ITA) in Salt Lake City. The group says it is the first program in the country to use dogs to help develop literacy in children, with the introduction of Reading Education Assistance Dogs (READ).

The Salt Lake City Public Library is sold on the idea. “Literacy specialists admit that children who read below the level of their fellow pupils are often afraid of reading aloud in a group, often have lower self-respect, and regard reading as a headache,” said Lisa Myron, manager of the children’s department.

Last November the two groups started “Dog Day Afternoon” in the children’s department of the main library. About 25 children attended each of the four Saturday-afternoon classes, reading for half an hour. Those who attended three of the four classes received a “pawgraphed” book at the last class.

The program was so successful that the library plans to repeat it in April, according to Dana Thumpowsky, public relations manager.

1.What is mainly discussed in the text?

A．Children’s reading difficulties.            B．Advantages of raising dogs.

C．Service in a public library.                 D．A special reading program.

2.Specialists use dogs to listen to children reading because they think _______.

A．dogs are young children’s best friends

B．children can play with dogs while reading

C．dogs can provide encouragement for shy children

D．children and dogs understand each other

3.By saying “The Salt Lake City Public Library is sold on the idea”, the writer means the library_______.

A．uses dogs to attract children

B．accepts the idea put forward by ITA

C．has opened a children's department

D．has decided to train some dogs

4.A “pawgraphed” book is most probably _______.

A．a book used in Saturday classes             B．a book written by the children

C．a prize for the children                   D．a gift from parent

Plants have family values, too; it seems, with new research suggesting they can recognize close relatives in order to work together.

An ability to tell family from strangers is well known in animals, allowing them to cooperate and share resources, but plants may possess similar social skills, scientists believe.

Susan Dudley and Amanda File of McMaster University in Ontario, Canada, report they have demonstrated for the first time that plants can recognize their kin.

This suggests that plants, though lacking recognition and memory, are capable of complex social interactions.

“Plants have this kind of hidden but complicated social life，” Dudley said.

The study found plants from the same species of beach­-dwelling wildflower grew aggressively alongside unrelated neighbors but were less competitive when they shared soil with their families.

Sea rocket, a North American species, showed stronger and healthier root growth when planted in pots with strangers than when raised with relatives from the same maternal(母系的) family, the study found.

This is an example of kin selection, a behavior common in animals in which closely related individuals take a group approach to succeeding in their environment, the researchers said.

Kin selection also applies to competition, because if family members compete less with each other, the group will do better overall. “Everywhere you look, plants are growing right up next to other plants，” Dudley said，“ Usually it’s a case of each plant for itself. But sometimes those plants are related, and there are benefits to not wasting resources on being competitive, and there is not really a cost to not being competitive as long as your neighbor is also not being competitive.”

Learning and memory appear to be important for kin recognition in animals, but this isn’t an option for plants, she noted.

Some researchers speculate(猜测) that plants communicate through their roots, identifying themselves using tiny chemical signatures specific to each plant’s family.

1.What’s the main idea of the message?

A．Studies find plants can recognize, communicate with relatives.

B．Kin selection is important for plants.

C．Animals can recognize and memorize their relatives.

D．Competition asks plants to recognize their relatives.

2.Which of the following is NOT right about animals’ social skill?

A．Animals can recognize and memorize their relatives.

B．Animals’ social skill is to cooperate and share resources.

C．Animals’ social skill can recognize close relatives in order to work together.

D．Animals’ social skill is no use at all.

3.Plants’ kin selection is to ________.

A．grow well                             B．compete with other kinds of plants

C．strengthen the relationship among siblings    D．find which one is the best

4.From the passage，we learn that ________.

A．sea rocket is a South American species

B．sea rocket grows aggressively alongside unrelated neighbors

C．sea rocket grows aggressively alongside its siblings

D．sea rocket is a kind of bush without flowers

5.How can the plants communicate with each other according to experts’ suppose?

A．Plants communicate by using tiny chemical signatures specific to each plant’s family.

B．Plants communicate with each other through their roots.

C．Plants communicate with each other by their leaves.

D．Plants communicate with each other with their flowers.