Imagine this: you sit down and begin to eat a tasty tomato when, suddenly, it starts to scream (尖叫). While this thing will never really happen, a new study showed that plants can make sounds when they are stressed.
Researchers from Tel Aviv University in Israel did the study. They used ultrasonic microphones (超声波麦克风) to record the sounds of tomato plants in boxes.
Three groups of plants were listened to : One group wasn’t watered for five days, another group had the stems (茎) cut off, and the third group, was untouched. It turned out that the first two groups made sounds 30 to 50 times per hour at a frequency(频率) of 40 to 80 kilohertz, while the untouched group only made the sound once per hour. “When tomatoes are not stressed at all, they are very quiet,” Lilach Hadany from the team told CNN.
The researchers don’t know how the sounds are made, but they believe the noise comes from the breaking of air bubbles in the plants. This means the noise produced by the plants is not intentional (故意的) or a form of active communication.
Although there’s no evidence(证据) that plants can intentionally communicate, animals and insects may be “listening in” to benefit from the sound. For example, the sound can tell moth that the plant is under stress and not suitable (合适的) to lay eggs on. An animal that wants to eat a plant could also use the sounds to make decisions, according to Science Focus.
After the experiment, the researchers listened to other plants such as wheat (小麦), corn and grapevine, and found they also made more sounds when stressed. Researchers said the study can benefit farmers in the future, as they can better take care of the crops(庄稼) by “hearing” how plants feel.
【小题1】What is the finding of the study by researchers from Tel Aviv University? ________A.Plants often feel stressed. |
B.Some plants can scream. |
C.Plants can make sounds when stressed. |
D.Plants can communicate with each other. |
A.A group that is fully-grown. |
B.A group which has its fruits picked. |
C.A group that is watered regularly. |
D.A group that has suitable temperature. |
A.Plants make sounds on purpose. |
B.Plants receive messages from animals. |
C.Plants make noise in a high frequency. |
D.Air bubbles in the plants can break. |
A.It may help improve crop production. |
B.It will help protect the environment. |
C.It can help farmers predict weather. |
D.It helps farmers decide what to plant. |
A.Plants can also “scream” | B.Tasty vegetables |
C.How can vegetables make sounds | D.Imagination about vegetables |
Everybody gets stressed from time to time. Some ways of dealing with stress, like screaming or hitting someone, don't solve (解决) much. But other ways, like talking to someone you trust, can lead you to solve your problem or at least feel better. Try taking these steps the next time you are stressed:
Get support. When you need help, reach out to the people who care about you. Talk to a trusted adult, such as a parent or other relatives. They might have ways to help you solve the problems, such as dealing with a test, or the death of a beloved pet.
Don't take it out on yourself. Sometimes when kids are stressed and upset, they take it out on themselves. Oh, dear, that's not a good idea. Remember that there are always people to help you. Be kind to yourself and ask for the helping hand to work out the problem.
Try to solve the problem. After you're calm and you have support from adults and friends, it's time to work out the problem. Even if you can't solve it all, you can solve a piece of it.
Be positive. Most stress is temporary(暂时的). Remember stress does go away, especially when you figure out the problem and start working on solving it.
These steps aren't magic, but they do work. And if you can stay positive as you make your way through a tough time, you'll help yourself feel better. Ah, it feels so good when the stress is gone.
【小题1】“Don't take it out on yourself.” means to ______ .A.keep busy all the time | B.behave in an unpleasant way towards yourself |
C.ask someone to help solve problems | D.get excited at something |
A.We can give up working it out. | B.We can stop to have a rest. |
C.We can solve part of the problem. | D.We can work out another problem. |
A.how to deal with stress | B.how to get relaxed |
C.how to solve problems | D.how to get help from others |
Monkeys are our close relatives(亲戚) in the animal world. Scientists have found that monkeys like to use one of their hands more than the other, but it can be either hand. There are as many right-handed monkeys as left-handed ones. Next time you visit a zoo, watch the monkeys carefully, you will see that some of them will use their right hands and others will use their left hands. But most of the people use their right hands better and this makes life difficult for those left-handed people. We live in a right-handed world.
【小题1】How many people among 100 people use their left hands better?
A.5%. | B.50%. | C.95%. | D.30% |
A.公正地 | B.均等地 | C.平凡地 | D.普通地 |
A.both of their hands | B.neither of their hands |
C.their right hands | D.their left hands |
A.There are more monkeys using their right hands than left hands. |
B.There are more monkeys using their left hands than right hands. |
C.There are as many right-handed monkeys as left-handed ones. |
D.There are not as many right-handed monkeys as left-handed ones. |
A.Most people use their right hands better. |
B.Few people use their right hands better. |
C.Half of the people use their right hands better. |
D.Some people use their right hands better. |
It might be fun to use your smartphone, but be careful. Too much screen time may be harmful to your health.
First, it is bad for your eyes. A researcher called Sarah Hinkley says the problem comes from the blue light that the screen gives out. Looking at a smartphone for a long time can cause eye strain, headaches and dry eyes. So it is a good idea to take a break every 15 minutes when you are working at a computer or using a smartphone.
Second, screen use can do harm to children’s brains. A new study shows that using screens too much can affect how children’s brains grow. If children use screens for more than one hour a day, they might have lower levels of white matter in their brains. White matter is a key to the development of language and reading skills. So it is wise to cut down the time of children using all kinds of screens.
Third, using screens too much will affect your sleep. According to a study, about 95% of the people between the ages of 13 and 64 use electronics before bed, especially the young people under 20. Doctors say that the light from those electronics at night may make you excited before you go to bed. Then it’s hard for you to get enough sleep. So you’d better turn off smartphones, TVs, and all other screens an hour before your bedtime.
To keep healthy, doctors and researchers strongly advise that you shouldn’t use screens for long hours.
【小题1】The blue light from your screens can make you have ______.A.eye strain | B.headaches | C.dry eyes | D.A, B, C |
A.take a break every 15 minutes | B.have lower levels of white matter |
C.use screens too much before bedtime | D.are the people from 13 to 64 |
A.The ways to keep healthy | B.The advantages of using screens. |
C.The ways of using screens | D.The disadvantages of using screens too much. |
A.a science magazine | B.a travel diary | C.a guidebook | D.a storybook |
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