【推荐1】People have known for a long time that plants can hear, see, smell and communicate with each other. Now, they have been recorded making sounds when stressed.

In a study, Itzhak Khait and his team found that tomato   and tobacco plants can make ultrasonic( 超声的 ) noises. The plant “cry out” due to lack of water, or when they are cut. The sound is just too high for human to hear.

Microphones were placed 10 centimeters away from the plants and picked up sounds in the range of 20 to 100,000 hertz( 赫兹). Human hearing usually ranges from 20 to 20,000 hertz. On average, “thirsty” tomato plants made 35 sounds an hour, while tobacco plants made 11. When plant was cut, tomato plants made an average of 25 sounds in the following hour, and tobacco plants 15.

Perhaps most interestingly, different types of stress led to different sounds. The researchers used a special machine to separate the plants’ sounds from those of wind, rain and other noises of the greenhouses. In most cases, it correctly told whether the stress was caused by dryness or a cut. Water-hungry tobacco made louder sounds than cut tobacco, for example. Although Khait and his team only looked at tomato and tobacco plants, they thought other plants also made sounds when stressed. Khait’s report also suggested that insects could hear the sound up to 5 meters away and respond.

The team said if farmers could hear these sounds, they could give plants the water they need. As climate change causes more droughts(干旱), they said this would be important information for farmers, for the sound that drought-stressed plants made could be used in agriculture.

If plants are screaming for fear of their survival, should we be thankful we can’t hear them?

1. Which did Khait and his team find from their research?

A．Only tomato plants could make ultrasonic noises.

B．Humans can hear plants crying while cutting them.

C．Plants were able to produce sounds when stressed.

D．Plants made ultrasonic noises to communicate with each other.

2. How did tomato and tobacco plants react to different stresses according to the text?

A．Cut tobacco plants made weaker sounds than drought-stressed ones.

B．Tomato plants reacted to different stresses with the same sound.

C．Cut tomato plants produced more sounds than water-hungry ones.

D．Tobacco plants made louder sounds than tomato plants when short of water.

3. What’s the main idea of Paragraph 5?

A．Farmers imagine what the future agriculture will be like.

B．Farmers have contributed a lot to the research.

C．Farmers can apply the result of the research to agriculture.

D．Farmers will face lots of challenges in the future.

4. Where is this text most likely from?

A．A nature magazine.

B．A novel.

C．A diary.

D．A guidebook.

【推荐2】If you've ever pulled a rolling suitcase through the airport, chances are that you've also been annoyed by this common occurrence: the suitcase starts rocking back and forth on each wheel and finally tips over.

"It's a very classic phenomenon in physics," said Sylvain Courrech du Pont, a physicist at the University of Paris Diderot. "So if you disturb the system it goes very easily unstable. This is shared by many, many phenomena in nature."

Courrech du Pont and his students wanted to get to the bottom of why luggage tips. So they built what looks like the structure of a wheeled suitcase, and then filmed it rolling on a treadmill (a machine for running). Then they modeled what they saw mathematically.

And here's what they found. Under normal rolling conditions, the forward motion of the suitcase is perpendicular(垂直的） to the wheels' axis of rotation（旋转轴）. All is good. But when you hit a bump or drag the handle fiercely and abruptly, one wheel lifts up. All of a sudden the pulling motion is no longer perpendicular to the still-rolling wheel's rotation axis, and the wheel corrects that by accelerating towards the center. But by that time the other wheel's coming down, the same thing happens, and now the suitcase is really rocking.

"And the first reaction you will have maybe is to slow down. But actually if you slow down you'll experience very big rocking. Therefore, the way back to a smooth ride is to keep up your speed," he says, "or move even faster, once rocking begins.

There are other solutions to suitcase instability—like doing a better packing job. "If you put heavy contents close to the axis of symmetry, then it will be stable, too."

And Courrech du Pont has one more piece of advice to avoid rocking in the first place: "If you go slow enough, it will always be stable." Keep that in mind, next time you're running to your gate.

1. What can we infer from the first two paragraphs?

A．Everyone has been upset by a rolling suitcase at the airport.

B．Physical phenomenon can be found in our daily life.

C．The disturbance of the system results from the instability of the suitcase.

D．The phenomenon of suitcase rolling is rare at the airport.

2. What mainly causes the suitcase rocking?

A．It hits a bump

B．One wheel lifts up.

C．One wheel falls down.

D．It is not perpendicular to the axis.

3. How do people react to a rocking suitcase firstly?

A．tip it over

B．accelerate its moving.

C．slow down its moving

D．drag its handle with great strength.

4. How many ways are mentioned to keep the suitcase stable in the text?

A．one	B．two
C．three	D．four

【推荐3】In general, people talk about two groups of colors: warm colors and cool colors. Researchers in psychology think that there are also two groups of people: people who prefer warm colors and people who prefer cool colors.

The warm colors are red, orange and yellow. Where there are warm colors and a lot of light, people usually want to be active. People think that red, for example, is exciting. Sociable people, those who like to be with others, like red. The cool colors are green, blue and violet. These colors, unlike warm colors, are relaxing. Where there are cool colors, people are usually quiet. People who like to spend time alone often prefer blue.

Red may be exciting, but one researcher says that time seems to pass more slowly in a room with warm colors than in a room with cool colors. He suggests that a warm color, such as red or orange is a good color for a living room or restaurant. People who are talking or eating do not want time to pass quickly. Cool colors are better for offices or factories if the people who are working there want time to pass quickly.

Researchers do not know why people think some colors are warm and other colors are cool. However, almost everyone agrees that red, orange, and yellow are warm and that green, blue, and violet are cool. Perhaps warm colors remind people of warm days and the cool colors remind them of cool days. Because in the north the sun is higher during summer, the hot summer sunlight appears yellow.

1. Which of the following colors belong to cool colors?

A．Yellow, green.	B．Blue, violet.
C．Black, blue.	D．Brown, white.

2. Which of the following statements is not true?

A．Sociable people like warm colors.

B．Warm colors can make people excited.

C．People who like to be with others don’t like red.

D．Where there are warm colors, people want to be active.

3. Which is the right color for different rooms?

A．Red or orange for offices.	B．Orange for dining-rooms.
C．Blue for bedrooms.	D．Red for studies.

4. What is the main idea of the last paragraph?

A．It shows the reason why people think some colors are warm and others are cool.

B．Warm colors remind people of warm days.

C．Cool colors remind people of cool days.

D．People have an agreeable opinion of warm colors and cool colors.

【推荐2】In today’s digital age when you can get information quickly, there is a concern about children developing an appreciation for reading printed books. That’s why communities in Australia have come up with a way to convey a love of books in the younger generations.

To solve this problem, communities are bringing libraries to where the kids are: in the streets. The little libraries consist of boxes that are set up outside of houses or public spaces and are filled with books. People can take books they haven’t read and donate ones they have to the libraries.

Street Library Australia, a nonprofit, was started by Nick Lowe after he saw a Little Free Library on a trip to the USA. After an initial workshop in 2015 to build 30 libraries, the idea mushroomed and now there are 4,500 registered street libraries in Australia. “It just grew and grew,” he said.

The libraries come in all shapes and sizes. These libraries are completely voluntary and anyone can start one.

Pamela Zielke, who runs a library called Pam’s Pantry, gives out toys and craft supplies along with books. An early childhood educator, she started her library with the goal of rescuing books from dustbins. But the libraries are doing much more than just providing books-and other donated items-to people. The street libraries are also building community. “It’s a little stopping place outside your house,” said Lowe. “It’s a great way to meet people in your neighborhood who are also book lovers, recycle books, and find new books.”

These Little Street Libraries provided a valuable service during the outbreak of COVID-19 and the popularity has not waned. People use them to find books on specific hobbies like cooking, children are developing a love of reading books, and it is more convenient than going to a bookstore or a brick-and-mortar library. But even more importantly, with a shared interest, the libraries are bringing communities closer together.

1. What might make people in Australia worried nowadays?

A．The popularity of digital books.	B．The poor service of community education.
C．The shortage of the street libraries.	D．Children losing interest in printed books.

2. What do we know about Nick Lowe?

A．He must be a citizen of the USA.

B．He was inspired by a trip to the United States.

C．He has set up a total of 30 street libraries in Australia.

D．He made a fortune through Street Library Australia.

3. What does the author intend to tell us by mentioning Pamela Zielke?

A．We should do all we can to support street libraries.

B．Many more street libraries will be set up in Australia.

C．Anyone can follow her example and start a street library.

D．It is of great benefit to run a street library in your neighborhood.

4. What does the underlined word “waned” in the last paragraph probably mean?

A．Turned weaker.	B．Become different.
C．Spread widely.	D．Won recognition.

【推荐3】If you’ re a student, developing the following skills will help you achieve success in school and in life.

Time management. High-school students have an average of 35 hours per week of class time and college students have an average of 15 to 18 hours per week. Manage your free time wisely and you'll make full use of each day.

Good study habits. If you’ve got them, it’s great. If not, there's still time to develop them. Good study habits include the following:

●Always be prepared for class, and attend classes regularly.

●Finish homework in a timely manner.

●Review your notes daily rather than study for tests the night before.

●Set aside quiet time each day for study, even if you don't have homework or a test the next day!

Good note-taking. Your can't possibly set down everything the teacher says since we talk at a pace of about 225 words per minute. But, you do need to set down the important materials. Note-taking should be in a way that's the most helpful to you. You can try writing notes on different colored cards. If you really have a problem with note-taking, you might ask your teacher if you can record daily lessons.Do whatever it takes.

Review of daily notes. Don't wait until the night before the test to review your notes. Go over your notes each day while the lecture is still fresh in your mind. Add any missing pieces. Compare your notes with a classmate's notes. Review your notes each day to improve your learning and build towards your final goal: mastery of the subject or skill.

1. What is the main advantage of reviewing daily notes?

A．To help write down the important materials.

B．To add any missing pieces to your notes.

C．To solve the problem with note-taking timely

D．To help you to master the subject greatly.

2. If you want to form good study habits, you should         .

A．get them as early as you can	B．go over your notes every day
C．study for tests the night before	D．set down all the teacher says

3. What's the best title for the passage?

A．Wise Time Use and Management

B．The Importance of Good Study Habits.

C．Tips for Students to Achieve Success.

D．Good Note-taking and Review of Daily Notes.