Young sunflowers turn and swing every day. New findings add to evidence that the plants are animal-like.
Harmer, a professor in the University of California at Davis’ Department of Plant Biology, carried out a series of experiments on sunflowers in the field, in pots outdoors and in indoor growth chambers.
By staking plants so that they could not move, Harmer showed that he could destroy their ability to track the sun. He also noticed that sunflowers prevented from moving were not as tough and leafy as those that were free to move. When plants were moved indoor with a settled overhead light, they continued to swing back and forth for a few days.
The indoor plants did start tracking the “sun” again when the apparent source of lighting was moved across the room. The plants could reliably track the movement and return at night when the artificial day was close to a 24-hour cycle, but not when it was closer to 30 hours.
When sunflowers track the sun, the east sides of their stems grew more rapidly than the west sides. At night, the west sides grew faster as the stem swung the other way. The team identified a number of genes that were expressed at higher levels on the sunward side of the plant during the day, or on the other side at night. A plant growth-regulating hormone, called auxin, appears to be a key driver.
The “dance” to the sun cycle obviously slows when the sunflower matures and its flowers open up. At that point, the plants stop moving during the day and settle down facing the sun in the east.
“Bees like warm flowers.” Harmer said, adding that the bees are cold-blooded, so landing on a warm flower saves them energy and perhaps feels really good.
“The morning warmth changes the flowers in a way to make them more appealing to insects, perhaps causing them to release more attractive scents earlier in the day.” he said. “We’re currently testing this idea.”
1.Why did Harmer do the experiment on sunflowers?
A.To see how sunflowers grow up.
B.To show what sunflowers’ genes are.
C.To study why sunflowers track the sun.
D.To check if sunflowers swing in cloudy days.
2.What does the underlined word “staking”(Par 3) probably mean in ?
A.Tracking. B.Fastening.
C.Preserving. D.Presenting.
3.What is the result of sunflowers being stopped from moving?
A.They won’t grow well.
B.They will grow faster than usual.
C.They won’t swing back though set free.
D.They will produce a number of new genes.
4.What would happen to the sunflowers if they became fully grown?
A.They would swing as usual.
B.They would move back and forth.
C.They would stop turning.
D.They would track the sun.
5.Bees are fond of dancing ______________.
A.on cold sunflowers B.in the circle of flowers
C.on warm sunflowers D.on the mature sunflowers
The chicken-loving dog spent last month guarding the island’s penguin colony, with great success.
A SOUTH-WEST Victorian chicken farmer known as Swampy and his dog Oddball may have found a way to save some of Australia’s endangered wildlife from enemies. After Warrnambool’s once flourishing penguin population was killed in large numbers by foxes and dogs until only 27 remained, Allan Swampy Marsh hatched an effective plan to save the birds. His four sheepdogs had been protecting his chickens against enemies for a decade. He figured they could do the same for the penguins. “The difficulty was trying to convince all the wildlife wallies to think outside the square,” Mr Marsh said. “It’s not an unselfish view of penguins or chicks but the sense of territory (领地) that makes the dogs work, and it is far stronger in these dogs than any other trained breed.”
Oddball’s work as guardian of Middle Island’s colony last month was a success. At the end of the month, 70 pairs of happy feet were counted returning to the island. About 2,000 penguins occupied the island in the 1990s. “Oddy is really protective of the chicks, so to her the penguins were only chicks in dinner suits,” Mr Marsh said. Highly territorial dogs have been bred in Italy to guard livestock for 2,000 years. They manage to keep off trouble makers such as foxes and dogs. The trial’s success has generated interest from overseas. The use of guard animals such as dogs — and even alpacas, which also stop foxes — is now being considered to save other endangered species such as the eastern barred bandicoot.
1.What had happened to most of Middle Island’s penguins?
A.They had been killed by other animals.
B.They had been scared away by people.
C.They had stopped breeding for no obvious reason.
D.They had been taken to another island for protection.
2.About how many penguins were on the island when it had the largest number?
A.27. B.70.
C.1990. D.2000.
3.What reminded Allan Marsh of using dogs to guard penguin?
A.Dogs’ interest.
B.Dogs guarding chicks.
C.Dogs’ believable strength.
D.Dogs’ training in protecting animals.
4.What feature of the dogs is most important in this story?
A.They come from Italy. B.They are very territorial.
C.They are an ancient breed. D.They are large with messy fur.
5.The purpose of the last paragraph is to suggest that________.
A.people should think globally but act locally
B.Allan ‘Swampy’ Marsh is a typical Australian
C.it may be possible to use this local idea more widely
D.every environmental problem needs a unique solution
We are admitted into the full-time school called “life”. Every day in this school, we have opportunities to learn new lessons. No matter whether we like these lessons or not, we have to take them, because they are our lessons.
Why are we here in this world? What is the purpose of life? Humans have tried to discover the meaning of life for thousands of years, but failed to get the answer, because the meaning of life is different from person to person.
Each one of us has his or her special purpose and path, unique and different. As we travel on our life path, we will learn many great lessons in order to fulfill that purpose. Learning our lessons well is the key to discovering the real meaning of our own life.
As we travel through our lifetime, we may be taught hard lessons that others don’t have to face, while others spend years struggling with problems we don’t need to deal with. We may never know why we love English, not physics, which indicates that our path is different. While traveling on our own path, sometimes alone, we should, first of all, take a basic lesson in openness.
Openness means being receptive. Life will present us with so many lessons, none of which are useful to us unless we can recognize them and are open to their values. These lessons are not easy to learn, but we should regard them as gifts. But how can we recognize these lessons? It is a matter of what “glasses” we are wearing at the time. It is not difficult to spot them if we take them as opportunities. So when we are not open to learning our lessons, failing a weekly English test might be like a disaster rather than an opportunity to us. Of course, the hard lessons may not be fun, but they can actually be the biggest gifts we receive from life.
1.The author may be in favor of the viewpoint that all men are born _______.
A.equal B.challenging
C.opportunistic D.different
2.The example of “we love English, not physics” is mentioned to show that _______.
A.we choose our own path in life
B.people have to face the same lessons
C.we should travel on the same path
D.we should enjoy the meaning of life
3.Whether we can see life lessons as gifts depends upon our________.
A.angles of view B.experiences from life
C.common value system D.willingness to face challenge
4.What would be the best title for the passage?
A.Life in School B.Gifts from Life
C.Life School and Students D.Life as School
5.What does the author imply at the end of the passage?
A.People always learn the same lessons.
B.Life is a lesson as one in the classroom.
C.Hard lessons are fun.
D.People should be open to the life.
Participants in an online forum were asked whether space exploration was worthwhile. Here are some of the comments they posted:
Planet Girl 7.17 pm
Our world is damaged by war, hunger and poverty. Billions of people struggle just to survive from day to day. Meanwhile the US space agency has US $16 billion to play with every year. We must deal with the world’s urgent problems. Space exploration is a luxury we cannot afford.
Dragon 7.18 pm
That $16 billion spent on space is nothing compared to the $370 billion spent on the military.
JJ 7.20 pm
Exploring space is investing in the future. Everyone knows we’re running out of resources. There’s massive over-population too. The solar system has heaps of resources we can use for mining, and maybe we can explore other planets. If we don’t do it now, it might be too late.
Planet Girl 7.22 pm
We have to settle problems of over-population and resource consuming here on Earth, instead of chasing science fiction dreams. Otherwise we will just export our unsustainable lifestyle to another planet. We might consume the whole universe!!
JJ 7.23 pm
Space explorers rock! They know what they are in for, and they still do it anyway. That’s what I call courage! We humans have always struggled to expand our horizons. We want to know what else is out there. Who knows, maybe we’ll discover the solution to all our problems out there!
Switched-on 7.25 pm
Space exploration has had a huge effect on our lives. Want to talk to someone halfway around the world? Sure. Get the weather forecast? Coming right up. Check exactly where you are? Absolutely. It’s all possible, thanks to satellite technology, global positioning systems, and the rest. If there was no space exploration, we’d be sitting around in the dark, not talking online!
Penny 7.50 pm
Satellites are launched by private companies — for profit. Planet Earth doesn’t always benefit. Exploring remote planets certainly does not contribute to life on Earth.
1.The underlined sentence (Par.2) means that space exploration is_________.
A.expensive but necessary
B.expensive and unnecessary
C.very important but too expensive
D.not very important but affordable
2.What is Dragon’s opinion?
A.The cost of space exploration is too much.
B.Planet Girl’s idea is acceptable.
C.Space exploration is worthwhile.
D.The military is more useful than space exploration.
3.What is the most likely reason that JJ does not discuss the cost of space exploration?
A.He agrees that space exploration costs too much.
B.He does not know how much space exploration costs.
C.He thinks space exploration is worthwhile, whatever the cost.
D.He knows Planet Girl is wrong about the cost of space exploration.
4.Which aspect of space exploration does Switched-on mainly write about?
A.Its cost to the community.
B.Its effect on environment.
C.Its contribution to technology in everyday life.
D.Its capacity to serve people in their everyday life.
5.What is one point that Planet Girl and JJ are most likely to agree about?
A.Living on other planets is a real possibility.
B.Spending money on war is unnecessary.
C.Space exploration encourages creativity.
D.Earth’s resources are fast disappearing.
One student took a box of chicken to class. Another carried on a cell-phone_______, and still another whistled loudly every time the_______turned his back. Reform school? No. College.
More and more, professors say, they are _______ across rude students in their classrooms. Many of today’s young scholars arrive late, leave_______, talk loud or take care of personal _______ such as paying bills during class.
Why are the students behaving badly? “Because they can,” said a student of University of North Texas. “A lot of the time, the professors _______them get away with it.”
Some educators say it is time to bring politeness back to their classrooms — and even_______taking some of the blame for bad behavior. They say that_______ students are by no means the majority but that one of them can ruin an entire_______.
People are ________when they learn that impolite behavior is becoming more and more common in ________education, says Dr. Gerald Amanda, a counselor at City College of San Francisco. They ________ some high school students to misbehave but think those who get to ________ will behave more politely.
Dr. Amanda believes that society in ________ has become more tolerant of rude behavior ________ that people in power, including professors, no longer ________ standards for politeness. That leads to a growing imprudence among some college________. “There’s a great ________ of bad behavior in the world around them, and young people see it and ________ disrespect,” said Dr. Amanda, ________ that sometimes students have no idea that they are being rude.
1.A.look B.news C.picture D.conversation
2.A.professor B.chick C.monitor D.classmate
3.A.getting B.coming C.cheating D.moving
4.A.alone B.early C.happily D.quietly
5.A.appearance B.interest C.computer D.affairs
6.A.let B.ask C.persuade D.lead
7.A.risk B.mind C.avoid D.start
8.A.rude B.poor C.beautiful D.good
9.A.lesson B.classmate C.subject D.class
10.A.moved B.inspired C.surprised D.encouraged
11.A.lower B.junior C.higher D.younger
12.A.expect B.want C.forbid D.warn
13.A.profession B.school C.knowledge D.college
14.A.motion B.time C.charge D.general
15.A.but B.so C.or D.and
16.A.set B.change C.break D.reach
17.A.teachers B.professors C.leaders D.students
18.A.deal B.number C.kind D.sum
19.A.prepare B.respect C.develop D.escape
20.A.speaking B.warning C.adding D.wishing
His food ______, the man had to come out of his hiding place.
A.run out B.was run out
C.running out D.using up
