When a leafy plant is under attack, it doesn’t sit quietly. Back in 1983, two scientists, Jack Schultz and Ian Baldwin, reported that young maple trees getting bitten by insects send out a particular smell that neighboring plants can get. These chemicals come from the injured parts of the plant and seem to be an alarm. What the plants pump through the air is a mixture of chemicals known as volatile organic compounds, VOCs for short.
Scientists have found that all kinds of plants give out VOCs when being attacked .It’s a plant’s way of crying out. But is anyone listening? Apparently. Because we can watch the neighbours react.
Some plants pump out smelly chemicals to keep insects away. But others do double duty. They pump out perfumes designed to attract different insects who are natural enemies to the attackers. Once they arrive, the tables are turned. The attacker who was lunching now becomes lunch.
In study after study, it appears that these chemical conversations help the neighbors .The damage is usually more serious on the first plant, but the neighbors, relatively speaking, stay safer because they heard the alarm and knew what to do.
Does this mean that plants talk to each other? Scientists don’t know. Maybe the first plant just made a cry of pain or was sending a message to its own branches, and so, in effect, was talking to itself. Perhaps the neighbors just happened to “overhear” the cry. So information was exchanged, but it wasn’t a true, intentional back and forth. Charles Darwin, over 150 years ago, imagined a world far busier, noisier and more intimate(亲密的) than the world we can see and hear. Our senses are weak. There’s a whole lot going on.
1.What does a plant do when it is under attack?
A.It makes noises. B.It gets help from other plants.
C.It stands quietly D.It sends out certain chemicals.
2.What does the author mean by “the tables are turned” in paragraph 3?
A.The attackers get attacked.
B.The insects gather under the table.
C.The plants get ready to fight back.
D.The perfumes attract natural enemies.
3.Scientists find from their studies that plants can ________.
A.predict natural disasters
B.protect themselves against insects
C.talk to one another intentionally
D.help their neighbors when necessary
4.What can we infer from the last paragraph?
A.The world is changing faster than ever.
B.People have stronger senses than before
C.The world is more complex than it seems
D.People in Darwin’s time were imaginative.
难度: 中等查看答案及解析
假定你是李华，你的英国朋友 Leslie 给你发邮件询问你在新型冠状病毒肺炎疫情期间是怎么度过。请你根据下列要点写一封邮件回复她:
1. 爆发时间； 2. 怎么度过； 3. 你的感受。
注意：1.词数 100 左右；
2.可以适当增加细节，以使行文连贯；
参考词汇：疫情 epidemic situation 新冠肺炎 novel coronavirus pneumonia
Dear Leslie,
________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________
Yours sincerely,
Li Hua
难度: 中等查看答案及解析
Have you ever wanted to feel like you were in a western film? Or maybe you wanted to feel like you were a pioneer traveling the west? It is possible to experience such things during a Wild West vacation! Here are four of the best Wild West vacation locations available:
Walk the Lewis and Clark Trail
Walk some or all of the 3,700 miles trail that was traversed by Mariwether Lewis and William Clark, two of the world's greatest explorers. Though not all the trails are marked, there are various stops that have been preserved by various historic societies. There is also a coach (长途客车)that makes a 16-day trek following the trail. This begins in St. Louis, Missouri, and ends in Astoria, Oregon.
Venture Route 66
Take a tour or go to see it yourself-ride on the famous Route 66. The road is nearly 2, 500 miles long. Harley Davidson offers motorcycle tours that last two weeks. Route 66 will provide an experience that may only be found on the open road. The historic road is still well taken care of.
Visit the Grand Canyon
Visit the most immense (巨大的)canyon in the world, located in Northern Arizona. Raft down the Colorado River, or hike the various trails that run throughout the canyon. If walking is not your thing, there are donkey and horse riding adventures available. In addition, there are motorized boats that float down through the canyon in a week's time.
Visit Deadwood
Located in South Dakota, Deadwood is a historic landmark. It is the kind of town that comes to mind when one thinks of an old western film. Actors who act as gunslingers (杀手）will often be seen in the streets playing their roles. Winter activities are popular in this old town, and there is always something to do.
1.What do we know from the passage?
A.None of the trails in the west are marked.
B.A number of historic stops aren't preserved well.
C.Western films are the most popular among Americans.
D.William Clark was a pioneer who explored the west.
2.The underlined word "trek" in Paragraph 2 can be replaced by" .
A.long and hard journey B.traveling information
C.beautiful scenery D.pleasant holiday
3.Which of the following riding adventures can tourists take on Route 66?
A.A horse riding adventure.
B.A coach riding adventure.
C.A motorcycle riding adventure.
D.A donkey riding adventure.
难度: 简单查看答案及解析
When I was a boy, our extended, immigrant family would sometimes gather at my aunt’s tiny house over the summer. Relatives from all over the country would come in to visit. The adults would crowd together in the living room to talk and catch up on each other' s lives. And the kids would be sent out into the front yard to play when dinner was slowly cooked for all of us.
Those were the days before video games, smart phones, and motorized toys, so we often ended up playing an old game. I remember one of those moments especially. As I was the youngest and smallest of all the kids there, I got caught first and couldn't catch anyone else. My brothers and cousins were all too fast for me, and I grew more and more frustrated. I finally fell my face first into the dirt. I got up with tears forming in my eyes. Then I saw one of my female cousins Susan standing there. She started to run but was going much slower than before. I easily caught up and seized her. Then she turned to me, smiled, and said, I'm it! You d better run! Iran off laughing with glee while she turned and started to chase others.
Now I see how her act of kindness that day saved me from sadness and returned me to joy. It didn't matter that we hardly ever saw each other. I know we are family and she loves me.
In her wonderful book: Box of Butterflies, Roma Downey writes, "We are all one, we all belong to each other, and we are one big. beautiful family." Perhaps it is time that we all started to treat each other that way. Perhaps it is time that we shared our love, our kindness, our laughter, and our joy with everyone without fear. Perhaps it is time to finally and forever bring this world together in one big family reunion.
1.When the adults were chatting, the kids would__________.
A.play video games B.sit in the front yard
C.learn to cook dinner D.play traditional games
2.The author was able to catch Susan because________.
A.the others ran too fast B.the author was good at running
C.Susan gave her a chance D.Susan wanted to chase others
3.What can be inferred from the passage?
A.The author is grateful for hat Susan did to her.
B.The author cant meet Susan any more.
C.The author urges others to love their family.
D.The author believes the world will become a big family
4.What could be the best title of the passage?
A.A memory of my childhood. B.Sharing of goodness unites us.
C.Kindness brightens our life. D.A good deed is invaluable.
难度: 中等查看答案及解析
Philo Farnsworth was a man who made it possible for one of the most important communication devices (设备）－ television to be created. Philo was born on August 19th, 1906, near Indian Creek in the western state of Utah. He attended a very small school near his family's farm. He did very well in school. He asked his teacher for special help in science. The teacher began helping Philo learn a great deal more than most young students could understand.
One night, Philo read a magazine story about the idea of sending pictures and sound through the air. Anyone with a device that could receive this electronic information could watch the pictures and hear the sound. The magazine story said some of the world's best scientists were using special machines to try to make a kind of device to send pictures.
14-year-old Philo decided these famous scientists were wrong and that mechanical devices would never work. He decided that such a device would have to be electronic. Philo knew electrons（电子）could be made to move extremely fast. All he would have to do was to find a way to make electrons do the work.
Very quickly Philo had an idea for such a receiver. It would trap light in a container and send the light on a line of electrons. Philo called it "light in a bottle".
Several days later, Philo told his teacher about a device that could capture (捕捉）pictures. He drew a plan for it, which he gave his teacher. Philo's drawing seemed very simple, but it clearly showed the information needed to build a television. In fact, all television equipment today still uses Philo's early idea.
Philo Farnsworth was only 14 years old then. He knew no one would listen to a child. In fact, experts say that probably only ten scientists in the world at that time could have understood his idea.
On September 7th, 1927, Philo turned on a device that was the first working television receiver. The image produced on the receiver was not very clear, but the device worked. In 1930, the United States government gave Philo patent documents. These would protect his invention from being copied by others.
1.How did Philo get the idea of inventing a television?
A.By learning from his science teacher.
B.By reading a story in a magazine.
C.By thinking hard on his own.
D.By using his knowledge about electrons.
2.The underlined word "it" in the fourth paragraph refers to .
A.a container sending pictures and sound through the air
B.a receiver that holds light and sends it on a line of electrons
C.a light box with a line of electrons in a bottle
D.a way to make electrons send pictures quickly
3.What can we learn about Philo?
A.His interest in science was raised by his teacher.
B.He made the first television receiver himself.
C.He received patent documents at the age of 24.
D.He found the famous scientists wrong after showing his teacher a plan.
4.We can infer from the text that Philo's idea .
A.was not recognized at first
B.was only understood by his teacher
C.was turned into a television receiver immediately
D.was widely used in all television equipment in 1927
难度: 中等查看答案及解析
A headache is a pain in the head which almost everyone feels at one time or another. Almost half of all people have a headache at least once a year. Most headaches are not dangerous but they get in the way of your work and disturb your life.
1.
Tension (紧张）headaches usually cause a slight to strong pain in the head. Many people describe such headaches as a tightening feeling. Some headaches cause a dull pain that can last for hours. They appear anywhere from the front to the back of your head.
About 20% of all headaches are migraines, which are strong headaches that can cause extreme pain. 2. You will have a feeling of sickness in the stomach, and sometimes you may see flashes of light shortly before migraines attack.
Causes of headaches
3.Even though the exact causes of a headache are not clear, most of them are caused by the widening of blood vessels (血管）combined with chemicals that are set free around them. Nerves send pain messages to your brain. There are many factors that can lead to a headache, such as lack of sleep, stress, smoking or watching TV for a long time. 4.
How to fight off headaches
Pain relievers (止痛剂）and other drugs are often used to ease headaches. Many people take aspirin when they have a headache. Doctors also suggest that patients should relax when they experience a headache. In some cases, changing your diet may result in relieving pain and weakening headaches.5. . This may not make headaches disappear completely but it can help make you feel better.
A.Types of headaches
B.Warning signs of migraine sufferers
C.They can last as long as a couple of days.
D.Headaches are a disorder of the nervous system.
E.And you should exercise regularly and get a lot of fresh air.
F.There are so many natural ways to relieve a violent headache.
G.Sometimes headaches can also be caused by injuries and sadness.
难度: 中等查看答案及解析
When we are young, we always dream of love and fulfillment. Perhaps we think of _______ nights or walks along the beach at sunset.
No one tells us that the greatest moments of a lifetime are short, unplanned and nearly always catch us off guard.
Not long ago, as I was _______ a bedtime story to my daughter, Annie, who was seven years old, I became aware of her _______look. She was _______ at me with a trancelike (着迷般的）expression. _______, completing The Tale of Samuel Whiskers was not as _______ as we first thought. I asked what she was thinking about.
"Mummy," she _______, "I just can't stop looking at your pretty face. I almost dissolved on the spot." I was deeply moved by her words. Little did she know how many _______ moments the glow of her sincerely loving _______would carry me through over the following years.
Not long after, I took my four-year-old ________ to an elegant, department store, where the sweet notes of a classic love song drew us toward a ________ playing the piano. Sam and I ________ down on a marble bench nearby, enjoying the ________ quietly and he seemed as astonished by the pleasant theme as I was.
I didn't realize that Sam had ________ next to me until he turned, took my face ________his little hands and said, "________ with me."
If only those women strolling under the moonlight had known the joy of such an________ made by a round cheeked boy with baby teeth. ________shoppers openly chuckled(咯咯笑），and pointed at us as we________around the open space, I would not have________a dance with such a charming young gentleman if I'd been offered the universe.
1.A.painful B.beautiful C.cold D.dark
2.A.reading B.writing C.retelling D.sending
3.A.scared B.focused C.careless D.anxious
4.A.studying B.watching C.glaring D.staring
5.A.Strangely B.Luckily C.Apparently D.Naturally
6.A.easy B.early C.simple D.important
7.A.whispered B.shouted C.cried D.introduced
8.A.exciting B.pleasant C.struggling D.casual
9.A.criticism B.statement C.position D.requirement
10.A.daughter B.son C.student D.cat
11.A.designer B.salesman C.manager D.musician
12.A.looked B.walked C.sat D.bent
13.A.music B.concert C.story D.scenery
14.A.stood up B.looked up C.picked up D.come up
15.A.with B.in C.by D.on
16.A.Sing B.Play C.Dance D.Go
17.A.invitation B.excuse C.experience D.agreement
18.A.Whether B.Whenever C.Since D.Although
19.A.looked B.wandered C.moved D.skated
20.A.expected B.traded C.accepted D.chosen
难度: 中等查看答案及解析
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。每处错误仅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)不计分。
Today we had a chemistry test. I found the test difficulty, but I tried hardly to do it. Suddenly Mary, my best friend, asking me to let her to copy my answers. After think for some time, I let her copy my answers. But after the test, all of us were called to the teacher’s office. The teacher was angry because we had same answers in the tests. We were warned not to cheat again, so she would need to call our parents. I was very upset. I didn’t cheat. I was just helping a friend. Why does she punish me?
难度: 中等查看答案及解析