Plants are certainly interesting and we have lots to learn about how they work, but can one plant pass along a message to another plant? Can that second plant receive the information and understand what it means? Modern research shows that they do communicate with each other and the two most important plant communication methods are chemicals and sounds.
Back in 1983, two scientists, Jack Schultz and Ian Baldwin, reported that young tree saplings (幼苗) getting bitten by insects could produce chemicals. Some chemicals moved through the plant causing other parts of the plant to produce a natural pesticide (除虫剂) which would discourage further feeding by insects. The chemicals also moved through the air. You and I wouldn’t notice, but these insects chemicals carried a slight smell that neighboring plants could notice and produced pesticides too. Over the past 20 years, scientists have found that many kinds of plants produce chemicals when they’re being attacked (袭击). It’s a plant’s way of crying out. But is anyone listening? Of course. Because the damage (伤害) is usually seen on the first plant, the neighbors stay well.
A new research, published in the journal Trends in Plant Science, has shown that plants also communicate with each other by making “clicking” sounds, which cannot be heard by the human ear, but they can be picked up by other plants. Using powerful loudspeakers, researchers were able to hear clicking sounds coming from the roots of corn saplings. Researchers also found that when they hung the young roots in water and played a continuous noise at 220 Hz, a similar frequency (频率) to the plant clicks, they found that the plants grew towards the source of the sound.
Plants are really great communicators. They are giving out lots of useful information to the environment. We are only just beginning to understand how this information is produced and how it is then picked up by other plants who can use it for their own benefit. So, the next time you step on some grass or pick a flower, remember that the poor plant might be crying at its neighbors, but we humans just cannot hear it!
1. Many plants ________ when they are bitten by insects.| A．give out chemicals |
| B．kill the insects with leaves |
| C．produce an awful smell |
| D．learn nothing about the attack |
| A．Plants have no natural abilities to protect themselves from insects. |
| B．The roots of the corn make clicking sounds when they are attacked. |
| C．Both chemicals and sounds made by plants are hardly noticed by people. |
| D．The same damage can usually be seen on a plant and its neighboring plants. |
| A．Why Do Plants Send Messages? |
| B．Do Plants Speak to Humans? |
| C．How Do Plants Communicate? |
| D．Do Plants Like Neighbors? |
2 . Is Losing Weight an Important Health Goal?
Advertisements, pop culture and even doctors can talk about health and weight as if they are one and the same: smaller bodies are healthier, and larger bodies must be unhealthy. But neither health nor bodies are that simple, and health can differ from person to person.
“A higher body mass index (BMI) has to do with health conditions like diabetes (糖尿病)”, said Philipp Scherer, a professor at the University of Texas. “However, it’s not that clear when researchers look at a single person.” People in smaller bodies can develop heart disease or diabetes, and plenty of people in larger bodies are considered completely metabolically (新陈代谢地) healthy. “It’s just a result of our genetic heterogeneity (遗传异质性) and how we do with calories (卡路里) more than needed,” he added.
Dr. Asher Larmie, a doctor in the UK noted, “BMI is just one of many factors causing changes in a person’s well-being. Medical care, environment, society and biology make up most of the factors that decide our health. We can’t take one look at a person's body and get a sense of their health. Can we see somebody’s medical records? Are we talking to their doctors? And often health is honestly sometimes out of our control (控制). There are so many illnesses that people just develop. ”
Then, how can we really keep healthy? Health is decided by many factors. Not falling ill is one, but so are staying mentally (精神地) healthy, keeping active social networks, getting enough sleep and lowering stress. Taking in fewer calories or cutting out certain foods may be bad for your health if it hurts your mental health or keeps you from enjoying time with friends and family.
“Weight loss doesn’t mean that you’ll necessarily get healthy. Sometimes how you lose weight could also be detrimental to your health. You may become unhealthy because of dieting,” said Charles Spence, a professor from the University of Oxford. “We should improve our health by moving more, sleeping better, stressing less and eating the foods your body is telling you that you need,” Larmie added.
1. What can we learn about health according to Dr. Asher Larmie?| A．Health is greatly under our control. |
| B．We can tell if people are healthy from their BMI. |
| C．Medical care is the most important for people’s health. |
| D．Many factors have to do with people’s health conditions. |
| A．mental health is less important than physical health |
| B．our lifestyle plays a very important role in our health |
| C．losing weight is a common way to help us keep healthy |
| D．sleeping better and stressing less can help us lose weight |
| A．improve | B．harm | C．serve | D．describe |
| A．To show us some useful ways to lose weight. |
| B．To tell us the importance of keeping healthy. |
| C．To make us clear on the relation between health and weight. |
| D．To call on us to keep a smaller body size through exercising. |
3 . Maybe you should sit down before you read this. You might feel afraid that your sitting may be killing you.
Health researchers say in the US, adults (成年人) now sit about 6.5 hours a day. That is up about an hour a day compared to 2007. The news is even worse for middle school students. The National Center for Health Statistics collected the numbers for the past 16 years and found that students sit 8 hours each day. The researchers are worried about this finding.
Too much sitting has bad effect (影响) on people. Study shows that people who do not often do outdoor sports can get ill more easily. People burn (燃烧) fewer calories (卡路里) so that they put on too much fat. They might even get serious illness such as heart problems. They are also at risk for high blood pressure (血压).
What do people do in the free time? About 60% of people in the US watch at least two hours of TV each day. That number doesn’t change much these years.
Computers are the biggest reason for more hours spent sitting. Computer use outside of work or school is going up for all age groups. Now, 50% of adults spend at least an hour of their free time on a computer each day. That is up from 29% in 2020. About 53% of middle school students now spend at least an hour of free time on computers. So do 56% of little children.
Standing up and doing sports help in lots of ways. It can burn more calories, make you happier and give you more energy (能量). It can also help you sleep better. So get up, take some breaks and go outside. You might save your life by doing outdoor activities. There are many choices for you.
1. The writer tells us that ________ is the biggest reason for more hours spent sitting.| A．the computer | B．the TV | C．the mobile phone | D．the paper book |
| A．Middle school students sit about 6.5 hours a day. |
| B．Middle school students spend 8 hours sitting each day. |
| C．About 53% of the students do outdoor activities each day. |
| D．50% of the students spend at least an hour on a computer a day. |
| A．What to do to burn more calories. | B．The disadvantages of using computers. |
| C．The cause and effect of too much sitting. | D．How to solve the problem of too much sitting. |
| A．Some health problems. | B．Some outdoor activities. |
| C．Several examples of sleeping well. | D．The importance of getting more energy. |
4 . Can you live without meals? Do you like eating breakfast? Someone ever said, “Eat well at breakfast; eat enough at lunch; eat less at supper. “Breakfast is the most important one.
Recently a test was given to people of different ages, from 12 to 80 in the United States. During the experiment (实验), these people were given all kinds of breakfast. And sometimes they got no breakfast at all. If they didn’t have breakfast, they would feel hungry, no energy or power. They could not work well. Their bodies work well when they eat a certain kind of breakfast. The results (结果) show that if people eat breakfast, he will work better.
So eating breakfast is good for our health. When you eat breakfast, food is the most important. It can give us enough energy so that we can work all day. A healthy breakfast could be bread, eggs, milk and fruit. If we eat breakfast before going to school, we will learn more quickly, and listen with more attention to class.
Get up earlier so that you would have enough time for your breakfast. Healthy breakfast can make you smile easily and make your life colorful.
1. How will the people feel if they don’t have breakfast according to (根据) the experiment?| A．They can work well. |
| B．They will feel hungry, no energy or power. |
| C．They will feel excited. |
| D．They will feel bored. |
| A．Bread and eggs. |
| B．Bread and fruit. |
| C．Milk and eggs |
| D．Hamburger and cola. |
| A．We will sleep well. |
| B．We will learn more quickly. |
| C．We will learn more slowly. |
| D．We will listen with more attention to class. |
| A．how to do an experiment |
| B．how to eat breakfast |
| C．what to eat for breakfast |
| D．why breakfast is important |
5 . In April 1961, Yuri Gagarin became the first man to travel in space. On July 20, 1969, Neil Armstrong became the first man to walk on the Moon. Some people believe the next step is for humans to visit Mars. It is sure that the first person to walk on Mars will become as Gagarin or Armstrong, and many astronauts would love the chance. But what is space travel really like for the astronauts?
Many astronauts suffer (承受) physical problems, even if they are in space for just a few months. Some of these problems are short-lived; others may be long-lasting. More than two-thirds of all astronauts suffer motion sickness (晕动病) while traveling in space. In space, the body cannot tell up from down and that can make the astronauts feel sick for a few days. More blood and water end up in the face, neck, and chest, resulting in a puff (肿胀) face and an enlarged heart. Being in a weightless environment (失重环境) means that astronauts do not use the muscles (肌 肉) so their muscles gradually get weaker. This, along with the change of blood to the upper body, astronauts lose some of important minerals (矿物质), and then their bones become weaker. As a result, many astronauts can’t walk well for a few days upon their return to Earth. In addition, they have to suffer the radiation (辐射) from the sun. This puts them at a higher risk of serious illness.
Besides the physical difficulties, astronauts who travel for long time may also suffer from psychological stress (压力). Long journeys need astronauts to spend more time inside a spaceship. For example, a round-trip journey to Mars could take about three years. Staying in a small space for such a long period of time is not healthy.
Astronauts—especially those who achieved important “firsts” such as Gagarin and Armstrong—are often seen as exciting adventurers.This may be right, but it’s also worth (值得) remembering the efforts they make to explore our universe.
1. According to Paragraph 2, what physical problem do astronauts suffer?| A．They may feel sick because of motion sickness. |
| B．Their hearts send weakened signals to their bodies. |
| C．They may live shorter after travelling in space. |
| D．Their brains often get less blood and water. |
| A．Less proper walks upon their return to Earth. |
| B．Weaker muscles and loss of important minerals. |
| C．More radiation from the sun hurting the bones. |
| D．Puffy faces, necks and enlarged hearts and brains. |
| A．To encourage people to be first one to visit Mars. |
| B．To question whether humans are able to go to Mars soon. |
| C．To remind us of the price astronauts pay for exploring universe. |
| D．To discuss what is the best health care for astronauts in space. |
6 . When we try something new, we often think that feeling uncomfortable means we’re in a situation that’s too hard to deal with. Embracing (接受) these feelings of stress and nervousness as a part of learning instead of heading back could help encourage personal growth, suggests a new study.
In the study, over 2,100 people took part in some personal growth activities, such as taking improv (即兴表演) classes or expressive writing classes. In each activity, researchers told some people that their goal was to feel uncomfortable, nervous, or even upset. They were told that feeling uncomfortable was a sign that the activity was working. Other people weren’t told to embrace discomfort; instead, they simply paid attention to learning something or how they were developing their skills.
Finally, the researchers found that the people who were told to try to feel uncomfortable were more involved in their activities, felt more encouraged to keep doing them, and reported a greater sense of achievement compared to those who weren’t told to experience discomfort. For example, some improv students spent more time on stage, and some writers were more interested in using expressive writing in their diaries.
“Growing is often uncomfortable. People always see the discomfort that comes with growth as a sign that there’s a problem. However, we should consider it as a sign of progress instead of avoiding it,” say the researchers.
If we learn to be comfortable with discomfort, we will grow stronger and make progress. The first step is to view discomfort differently. Look at discomfort as a sign that we are improving our lives and experiencing growth. Then do instead of thinking. Rather than think about how difficult or uncomfortable a task might be, just do it. Whatever we do, try to go a little past that point when we start feeling like we want to give up or when we are uncomfortable and want to take a break: run one more minute or kilometer than last time or write one more paragraph.
No pain, no gain (收获). It’s true! When we push ourselves to grow, we will experience discomfort, but it will be worth it.
1. What can we learn from the study mentioned in the passage?| A．Experiencing little discomfort leads to great success. |
| B．The attitude towards discomfort influences personal growth. |
| C．The feeling of discomfort encourages people to try new things. |
| D．Paying attention to what you’re learning weakens your discomfort. |
| A．The ways to manage discomfort. |
| B．The suggestions to avoid discomfort. |
| C．The benefits of embracing discomfort. |
| D．The reasons to view discomfort differently. |
| A．I try to speak in public although it makes me nervous. |
| B．I start swimming when I find running is a bit challenging. |
| C．I keep quiet in class because I’m afraid to answer questions. |
| D．I don’t like singing before strangers, so I always sing to myself. |
| catch1/kætʃ/v caught, caught, catching 1 ▶HOLD◀ [I, T] to get hold of and stop something that is moving through the air: Denise caught the bride’s bouquet.∣ Here’s your red ball, Sammy. Catch! |
| You won’t catch me ironing his shirts! 17 Catch you later! used in order to say goodbye catch on phr v [I] 1 to begin to understand something: Usually a couple of the children will catch on quickly and help the others. 2 to become popular: Rollerblades have sure caught on-you see them everywhere now. catch up phr v [I] 1 to come up from behind someone or something and reach the same point: I had to run to catch up with her. 2 to reach the same standard or level as someone or something else: The US spent a lot of money trying to catch up with/to the Soviet Union in space exploration. catch up on sth phr v [T] to do something that needs to be done that you have not had time to do in the past: I need to catch up on some work. catch2 n 1 the act of catching something that has been thrown or hit: That was a great catch! 2 [U] a game in which two or more people throw a ball to each other. Let’s play catch. 3 INFORMAL a hidden problem or difficulty: The rent is so low there must be a catch. 4 a quantity of something that has been caught, usually fish: a large catch of tuna fish 5 a hook for fastening something and holding it shut: the catch on my necklace Catch-22/,kætʃtwεnti’tu/ n [singular, U] a situation that you cannot escape from because of something that is part of the situation itself: You can’t get a job without experience, and you can’t get experience without a job. It’s a Catch-22. catch·er /’kætʃə/ n the baseball player who SQUATs behind the place where the BATTER |
| 2 ▶FIND SB STH◀ [T] to stop and hold someone or something after you have been chasing or hunting him, her, or it: Look at all the fish we caught, Wes. 3 ▶SEE/SMELL◀ [T] to see or smell something for a moment: I suddenly caught sight of Luisa in the crowd.∣ Yuck-did you catch a whiff of his aftershave? (=did you smell it?) 4 catch sb’s eye to make someone notice someone or something: A photograph on his desk caught my eye. 5 ▶GET SICK◀ [T] to get an illness: Put your coat on! You don’t want to catch (a) cold! 6 catch (on) fire to start burning, especially accidentally 7 catch your breath to begin breathing normally again after you have been running or exercising 8 ▶NOT BE TOO LATE◀ [T] to not be too late to do something, talk to someone etc.: I’m catching the 7:30 bus.∣ If you hurry you might catch her before she leaves. 9 ▶FIND SB DOING STH◀ [T] to find someone doing something wrong or illegal: I caught him sleeping with another woman.∣ A store detective caught him red-handed. (=saw him stealing) 10 ▶ATTACHED◀ [I, T] to become attached | ||
| A．getting an illness |
| B．finding someone doing something wrong |
| C．seeing something for a moment |
| D．taking hold of somebody or something |
| A．catch you later | B．Catch-22 | C．catch on | D．catch your breath |
There are a lot of plants in the world. Plants are very important. This is because plants can make food for us from air, water and sunlight. Animals and man cannot make food from air, water and sunlight. Animals can get their food by eating plants and other animals. Man gets his food by eating plants and animals, too. So animals and man need plants in order to(为了) live. This is why there are so many plants around us.
There are two kinds of plants: flowering plants and non-flowering plants. Almost all the trees around us are flowering plants. You can know some trees from their flowers and fruit. Non-flowering plants do not grow flowers. You cannot see many non-flowering plants around you.
Look carefully at the plants around you, and you can find there are many kinds of plants. Some plants are large and some are small. Most of them are green. Thanks to the plants around us, we can live on earth.
1. Why are plants very important?2. Can we make food from air, water and sunlight?
3. How many kinds of plants are there according to the passage?
4. What color are most of the plants?
5. What’s the passage mainly about?
Scientists have found the world’s largest sea grass meadow (草坪). They did it by using videos taken by some unusual helpers: tiger sharks.
The work should help protect (保护) the sea grass, and it’s also an interesting way to learn about the ocean (海洋).
Sea grasses help clean the ocean’s water, and provide (提供) food and living places for many sea animals. Importantly, they help in fighting global warming.
Scientists want to protect them, but they don’t have a good idea of where and how large they are. Sea grasses can be hard to see because the water is too deep and not clear enough. As a scientist said, “If we don’t know where it is, we can’t protect it.”
So scientists want sharks to help with the research (研究). Tiger sharks are huge, strong, fast swimmers and also spend a lot of time in sea grass meadows. The scientists put cameras on the fins of sharks and then let them go back to the ocean.
The cameras fell off after a few hours and floated (漂浮) to the top of the ocean. Tracking signals (追踪信号) helped the scientists find the floating cameras and collect the videos the sharks had taken. Putting all this information together, the scientists found the largest sea grass meadow.
The research also shows how useful large underwater animals can be in helping to learn more about life under the sea. A scientist said, “Animals like tiger sharks are going to take us to completely new places.”
1. Who are the scientists’ unusual helpers in the passage?2. Why is it hard for the scientists to find the sea grasses?
3. How did the scientists find the floating cameras?
4. What does the writer want to tell us in the last paragraph?
10 . Most people around the world are right-handed (右撇子). This also seems to be true in history. In 1799, scientists studied works of art made at different times from 1,500 B.C. to the 1950s. Most of the people shown in these works are right-handed, so the scientists guessed that right-handedness has always been common through history. Today, only about 10% to 15% of the world’s population is left-handed.
Why are there more right-handed people than left-handed ones? Scientists now know that a person’s two hands each have their own jobs. For most people, the hand is used to find things or hold things. The right hand is used to work with things. This is because of the different work of the two sides of the brain. The right side of the brain, which makes a person’s hands and eyes work together, controls the left hand. The left-side of the brain, which controls the right hand, is the centre for thinking and doing problems. These findings show that more artists should be left-handed, and studies have found that left-handedness is twice as common among artists as among people in other jobs.
No one really knows what makes a person become right-handed instead of left-handed. Scientists have found that almost 40% of the people become left-handed because their main brain is damaged when they are born. However, this doesn’t happen to everyone, so scientists guess there must be another reason why people become left-handed. One idea is that people usually get right-handed from their parents. If a person does not receive the gene (基因) for right-handedness, he/she may become either right-handed or left-handed according to the chance and the people they work or live with.
Though right-handedness is more common than left-handedness, people no longer think left-handed people are strange or unusual. A long time ago, left-handed children were made to use their right hands like other children, but today they don’t have to.
1. After studying works of art made at different times in history, the scientists found ________.| A．the art began from 1,500 B.C. |
| B．the works of art ended in the 1950s |
| C．most people shown in the works of art are right-handed |
| D．most people shown in the works of art are left-handed |
| A．Less than one sixth. | B．More than a half. |
| C．About 40%. | D．The passage doesn’t tell us. |
| A．No one really knows what makes a person become right-handed. |
| B．Scientists think there must be some reason why people become left-handed. |
| C．Today children are not made to use their right hands only. |
| D．Left-handedness is cleverer than right-handedness. |
