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 cast sides of their stems grew more rapidly than the west sides. Ai 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 “slaking” probably mean in Paragraph 3?
A.Tracking. B.Fastening.
C.Preserving. D.Researching.
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 is the advantage of sunflowers’ dance to the sun?
A.They attract more insects. B.They save more energy.
C.They mature more rapidly. D.They produce more flowers.
The crocodile (鳄鱼) is an amazing animal. Why are they amazing? Crocodiles are experts at survival. Scientists say they first appeared 200 million years ago and have lived longer than the dinosaurs by some 65 million years. One reason why they are such good survivors is that they can go for a very long time without eating. And they are expert hunters! They use their strong jaws to bite their prey (猎物) and then they swallow food whole. Another amazing fact about crocodiles is: When they lose a tooth, they grow one right back. A crocodile can go through 8,000 teeth in one lifetime!
While these facts are interesting, they really do not help to explain today’s expression: crocodile tears. Simply put, crocodile tears are fake sadness. You pretend to cry and feel bad or something when in fact you could not care less. A great word to describe crocodile tears is insincere.
The expression “crocodile tears” comes from an old story that crocodiles would cry tears as a fake show of guilt or sorrow to trick their prey. The prey would come closer and then become dinner. We know now that the story is not true. Scientists explain that crocodiles do produce tears. That is because while eating, they swallow too much air; which gets in touch with lachrymal glands (glands that produce tears) and forces tears to flow. But they’re not actually crying. Crying is purely emotional and is reserved for us humans.
When you use it, take some advice. You do not have to have actual tears flowing down your face to have “crocodile tears”. Sometimes, crocodile tears are worse than insincere. Those are the times when you are showing sadness but actually in your heart, you are quite happy about the situation.
1.How does the author mainly show that crocodiles are amazing?
A.By telling stories. B.By giving examples.
C.By conducting experiments. D.By making comparisons.
2.“Crocodile tears” is often said to a person who________ .
A.has some insincere friends B.faces sorrowful situations
C.shows unreal sadness D.cares little about others
3.Why does a crocodile produce tears according to scientists?
A.The flow of its tears makes it appealing. B.It pretends to be guilty to trick its prey.
C.It wants to show its emotional feelings. D.The way it eats forces its tears to flow.
4.What is the best title for the text?
A.An Expression — “Crocodile Tears” B.What Crocodiles Actually Cry for
C.Unknown Facts About Crocodiles D.How Crocodiles Show Sadness
Every man wants his son to be somewhat of a clone, not in features but in footsteps. As he grows you also age, and your ambitions become more unachievable. You begin to realize that your boy, in your footsteps, could probably accomplish what you hoped for. But footsteps can be muddied and they can go off in different directions.
My son Jody has hated school since day one in kindergarten. Science projects waited until the last moment. Book reports weren’t written until the final threat.
I’ve been a newspaperman all my adult life. My daughter is a university graduate working towards her master’s degree in English. But Jody? When he entered the tenth grade he became a “vo-tech” student (技校学生). They’re called “motorheads” by the rest of the student body.
When a secretary in my office first called him “motorhead”, I was shocked. “Hey, he’s a good kid, ” I wanted to say. “And smart, really.”
I learned later that motorheads are, indeed, different. They usually have dirty hands and wear dirty work clothes. And they don’t often make school honor rolls (光荣榜).
But being the parent of a motorhead is itself an experience in education. We who labor in clean shirts in offices don’t have the abilities that motorheads have. I began to learn this when I had my car crashed. The cost to repair it was estimated at $800. “Hey, I can fix it,” said Jody. I doubted it, but let him go ahead, for I had nothing to lose.
My son, with other motorheads, fixed the car. They got parts from a junkyard, and ability from vo-tech classes. The cost was $25 instead of $800.
Since that first repair job, a broken air-conditioner, a non-functioning washer and a non-toasting toaster have been fixed. Neighbours and co-workers trust their car repairs to him.
These kids are happiest when doing repairs. They joke and laugh and are living in their own relaxed world. And their minds are bright despite their dirty hands and clothes.
I have learned a lot from my motorhead: publishers need printers, engineers need mechanics, and architects need builders. Most important, I have learned that fathers don’t need clones in footsteps or anywhere else.
My son may never make the school honor roll. But he made mine.
1.What used to be the author’s hope for his son?
A.To avoid becoming his clone. B.To resemble him in appearance.
C.To develop in a different direction. D.To reach the author’s unachieved goals.
2.What can we learn about the author’s children?
A.His daughter docs better in school.
B.His daughter has got a master’s degree.
C.His son tried hard to finish homework.
D.His son couldn’t write his book reports.
3.The author let his son repair the car because he believed that .
A.his son had the ability to fix it B.it would save him much time
C.it wouldn’t cause him any more loss D.other motorheads would come to help
4.What did the author realize in the end?
A.It is unwise to expect your child to follow your path.
B.It is important for one to make the honor roll.
C.Architects play a more important role than builders.
D.Motorheads have greater ability than office workers.
When you're having a hard time with your homework or when you're preparing for your term paper, these student-focused websites can help you with just about anything you need. The key to getting the most out of these online resources is to know how they can best be used to your advantage.
Although Facebook can be one of your biggest time-wasters and distractions when you are supposed to be getting work done, it can also be one of your most valuable resources. Most of your classmates will probably have a Facebook account, so anyone you need to connect with about a class you missed or about a problem is usually just a few clicks away.
Amazon, com
Do you finish every term with many expensive textbooks you will never open again? Instead of letting the money spent go to waste, get back some of your cash by selling your books on Amazon.
RateMyProfesSors.com
Choosing new classes can sometimes be like trying to pick out your clothes in the dark, a total guessing game. Which teacher gives out the hardest problem sets? How much homework will that history professor give you every week? At RateMyProfessors. com, students all over the country rate their professors on quality, helpfulness, and how hard their classes are.
Wikipedia
While Wikipedia isn't aimed specifically at students, it is difficult to think of another website that does more to reduce the pain of paper writing and researching. Wikipedia gives you a quick way to find sources and get the details of almost any topic you need to research— all without walking to the library.
1.The passage was mainly written to .
A.explain some websites for parents B.offer some websites that may help students
C.compare some educational websites D.introduce different parts of a website
2.While you are taking great pains to write a research report, can most probably be a help.
A.Facebook B.Amazon.com C.RateMyPorfessors. com D.Wikipedia
3.RateMyPorfessors. com is a place_________.
A.where you can make friends all over the country
B.where you can communicate with your professors
C.that gives you information about professors in advance
D.that gives tips on how to get along with your professors
假定你是李华，China Daily正在征集一封英文感谢信，以致敬奋战在抗击新型冠状 病毒肺炎第一线的医护人员，请你代表学校写一封信投稿，要点如下：
1. 表达感激；
2. 个人感受；
3. 表达信心。
注意：1.词数100左右；
2.可以适当增加细节，以使行文连贯；
3.开头语和结束语己为你写好。
参考词汇：流行病epidemic 新型冠状病毒novel coronavirus
Dear Medical workers,
______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________
Yours sincerely,
Li Hua
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：在错的词下面划一横线，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）不计分。
It was 7:15 in the morning of February 8, 2020. I was walking along Park Road towards the east while an old man came out of the park on the other sides of the street. Then I see a yellow car drive up Milton Street and turn the right into Park Road. The next moment, the car hit the man while she was crossing the road. He fell with a cry. To surprise, the car didn’t stop and drove off at full speed. I noticed the driver was a young woman wore a pair of glasses but the plate number was AC864. Two minutes late, I stopped a passing car and took the old man to the nearest hospital.
