Have you ever wondered why the roots of the plants always know which way to grow—into the soil but not above it? Some British scientists have recently solved this mystery.

It turns out that roots have special hairs that tie them into the soil and help them grow their way past obstacles, a team at the John Inners Center in Norwich reports in the February 29 issue of Journal Science.

“The key is in the fuzzy(有绒毛的)coat of hairs on the roots of plants,” says professor Liam Dolan. “We have found a growth control system that enables these hairs to find their way and to become longer when their path is clear.”

Root hairs explore the soil in much the same way a person would feel their way in the dark. If they come across an obstacle, they make their way around until they can continue growing in an opening. In the meantime, the plant is held in place as the hairs grip(紧紧抓住)the soil.

The hairs are guided by a clever chemical trick. A protein(蛋白质) at the tip of the root hairs called RHD2 helps them to take calcium(钙) from the soil. Calcium makes the hairs grow, and produce more RHD2, and take more calcium.

But when an obstacle blocks the hair’s path, or the hair reaches the surface of the soil, the cycle is broken and growth starts in another direction.

This system gives plants the flexibility to explore a complex environment and to live in even the most unpromising soils, says Dolan.

In poor soils such as in parts of Australia and Africa, native plants have adapted by producing enormous numbers of root hairs. A better understanding of this adaptation will allow scientists to develop hairy rooted crops that can grow in unfriendly environments.

According to Dolan, “Research in the John Inners Center is taking a breeding approach to increase hair length in wheat but it will be some time before new cultivars(栽培变种) are developed.”

1.The passage is mainly about _______.

2.How does the circle work?

3.We can infer from the last paragraph that ________.

How to Be a Winner

Sir Steven Redgrave  

Winner of 5 Olympic Gold Medals  

“In 1997 I was found to have developed diabetes （糖尿病） . Believing my career （职业生涯）was over, I felt extremely low. Then one of the specialists said there was no reason why I should stop training and competing. That was it----the encouragement I needed. I could still be a winner if I believed in myself. I am not saying that it isn’t difficult sometimes. But I wanted to prove to myself that I wasn’t finished yet. Nothing is to stand in my way.”  

Karen Pickering  

Swimming World Champion  

“I swim 4 hours a day, 6 days a week. I manage that sort of workload by putting it on top of my diary. This is the key to success―you can’t follow a career in any field without being well-organized. List what you believe you can achieve. “Trust yourself, write down your goals for the day, however small they are, and you’ll be a step closer to achieving them.”  

Kirsten Best  

Poet ＆ Writer  

“When things are getting hard, a voice inside my head tells me that I can’t achieve something. Then, there are other distractions, such as family or hobbies. The key is to concentrate. When I feel tense, it helps a lot to repeat words such as ‘calm’, ‘peace’ or ‘focus’, either out loud or silently in my mind. It makes me feel more in control and increases my confidence. This is a habit that can become second nature quite easily and is a powerful psychological （心理的） tool.”  

 　　60. What does Sir Steven Redgrave mainly talk about?

　　A. Difficulties influenced his career.

　　B. Specialists offered him medical advice.

　　C. Training helped him defeat his disease.

　　D. He overcame the shadow of illness to win.

　　61. What does Karen Pickering put on top of her diary?

　　A. Her training schedule.

　　B. Her daily happenings.

　　C. Her achievements.

　　D. Her sports career.

　　62.What does the underlined word “distractions” probably refer to？

　　A. Ways that help one to focus.

　　B. Words that help one to feel less tense.

　　C. Activities that turn one's attention away.

　　D. Habits that make it hard for one to relax.

　　63. According to the passage ,what do the three people have in common?

　　A. Courage.

　　B. Devotion.

　　C. Hard work.

　　D. Self-confidence.

假定英语课上老师要求同桌之间交换修改作文，请你修改你同桌写的以下作文。文中共有10处语言错误，每句中最多有两处。错误涉及一个单词的增加、删除或修改。
增加：在缺词处加一个漏字符号∧,并在其下面写出该加的词。
删除：把多余的词用斜线/ 划掉。
修改：在错的词下划一横线，并在该词下面写出修改后的词。
注意：1 每处错误及其修改均仅限一词；
2 只允许修改10处，多者（从第11处起）不记分。
Jim is one of my closely friends. Two months ago，his mother bought a computer
to him as a birthday present. She hoped Jim will study hard with the help of the
computer. To his surprise，Jim just wasted plenty of time play computer games every
day. Now she regrets buying the computer. As matter of fact，a computer can do a lot of
everyday jobs for us. It is wide used in factories，hospitals，banks and so on. Many
computers scientists are now trying to make the computer to “think” like a man. In my
opinion，the key is what we should use it wisely.

  Moods (心情), say the experts, are feelings that are likely to become fixed, having effects on one’s outlook(way of looking at things) for hours, days or even weeks. That’s great if your mood is a pleasant one, but a problem if you are sad, anxious, angry, or simply lonely.

  Perhaps the best way to deal with such moods is to talk them out; sometimes, though, there is no one to listen. Scientists offers a lot of tranquilizers(镇静剂) and anti-anxiety drugs. What many people don’t realize, however, is that scientists have discovered the effectiveness of several non-drug methods to make you free from an unwanted mood. These can be just as useful as drugs, and have the added benefit of being nonpoisonous(无毒的). So next time you feel out of sorts, don’t head for the drug store―try the following method.

  Of all the mood-changing self-help techniques, aerobic exercises (有氧运动) seem to be the best cure for a bad mood. “If you could keep the exercise, you’d be in high spirits,” says Kathryn Lance, author of Running for Health and Beauty.

  Researchers have explained biochemical and various other changes that make exercises compare favorably to drugs as a mood-raiser. Physical work such as housework, however, does little. The key is aerobic exercises – running, cycling, walking, swimming, or other repetitive and sustained activities that increase the heart rate and circulation(循环), and improve the body’s use of oxygen. Do them for at least 20 minutes a time, three to five times a week.

It can be inferred from the passage that __________.

 A. when one is in a bad mood, he or she must not work very well.

 B. the best way to overcome a bad mood is to talk to oneself

 C. some drugs are more effective than physical exercises

 D. taking drugs is at risk of being poisonous

The phrase "feel out of sorts", as is used in the second paragraph, could be best replaced by ____________.

   A. put things in order                               B. are in a bad mood    

   C. search for tranquilizers                             D. want a mood-raiser

Which of the following best describes the organization of this passage?

 A. An exercise and its importance are explained     

 B. A problem is examined and solutions are given

 C. Two different views of a problem are presented   

 D. Recent developments in medicine are described

How to Be a Winner

Sir Steven Redgrave

Winner of 5 Olympic Gold Medals

       “In 1997 I was found to have developed diabetes （糖尿病） ．Believing my career （职业生涯）was over, I felt extremely low．Then one of the specialists said there was no reason why I should stop training and competing．That was it----the encouragement I needed．I could still be a winner if I believed in myself．I am not saying that it isn’t difficult sometimes．But I wanted to prove to myself that I wasn’t finished yet．Nothing is to stand in my way．”

Karen Pickering

Swimming World Champion

       “I swim 4 hours a day, 6 days a week．I manage that sort of workload by putting it on top of my diary．This is the key to success—you can’t follow a career in any field without being well-organized．List what you believe you can achieve．“Trust yourself, write down your goals for the day, however small they are, and you’ll be a step closer to achieving them．”

Kirsten Best

Poet ＆ Writer

       “When things are getting hard, a voice inside my head tells me that I can’t achieve something．Then, there are other distractions, such as family or hobbies．The key is to concentrate．When I feel tense, it helps a lot to repeat words such as ‘calm’, ‘peace’ or ‘focus’, either out loud or silently in my mind．It makes me feel more in control and increases my confidence．This is a habit that can become second nature quite easily and is a powerful psychological （心理的） tool．”

What does Sir Steven Redgrave mainly talk about?

       A．Difficulties influenced his career．

       B．Specialists offered him medical advice．

       C．Training helped him defeat his disease．

       D．He overcame the shadow of illness to win．

What does Karen Pickering put on top of her diary?

       A．Her training schedule．       B．Her daily happenings．

       C．Her achievements．          D．Her sports career．

What does the underlined word “distractions” probably refer to?

       A．Ways that help one to focus．

       B．Words that help one to feel less tense．

       C．Activities that turn one’s attention away．

       D．Habits that make it hard for one to relax．

According to the passage, what do the three people have in common?

       A．Courage．     B．Devotion．    C．Hard work．        D．Self-confidence．