【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?

【推荐2】Everybody hates rats (big mice). But in the earthquake capitals of the world — Japan, Los Angeles and Turkey — rats will soon be man’s best friends.

What happens after an earthquake？We send in rescue dogs. Why？Because they can smell people. Dogs save lives. They help rescuers to find living people. But dogs are big and they can’t get into small spaces. So now a new research project is using a smaller animal to save lives: the rat.

How does it work？First, the rat is trained to smell people. When this happens, the rat’s brain gives a signal (信号). This is sent to a small radio on its back, and then the rescuers follow the radio signal. When the rat’s brain activity jumps, the rescuers know that someone is alive. The rat has smelled that person.

Although there are already robots which can do this job, rats are better. Christian Linster at Cornell University, New York, says, “Robots’ noses don’t work well when there are other smells around. Rats are good at that.” Rats can also see in the dark. They are cheaper and quicker to train than dogs, and unlike robots, they don’t need electricity!

The “rat project” is not finished, but Julie Ryan of International Rescue Organization in Scotland says, “It would be wonderful. A rat can get into spaces we can’t get to, and a rat will get out if it isn’t safe.” Perhaps for the first time in history, people will be happy to see a rat in a building (but only after an earthquake, of course).

【推荐2】There was a man playing the piano in a bar. He was a good piano player and always performed in this bar. People came in just to hear him play. But one night, a customer told him that he didn’t want to hear him just play the piano any more. He wanted him to sing a song.

The man said, “I don’t sing.”

But the customer was persistent. He told the bar manager, “I’m tired of listening to the piano. I want that man to sing!”

The manager shouted across the room, “If you want to get paid, sing a song. Our customers are asking you to sing!”

So he did. He sang a song. A piano player who had never sung in public did so for the first time. And everyone was surprised by his song — Mona Lisa. He got lots of applause (掌声) that night.

He had such a talent for singing, but he just had been sitting on his talent for the past years! If without such a chance, he may have lived the rest of his life as a no-name piano player in a no-name bar. However, now he had become one of the best-known singers in America.

You, too, have skills and abilities. Maybe your “talent” is not as great as the singer above, but it may be better than you think! And with effort, most skills can be improved. So, in your life, you should be brave enough to try doing different things and find out what talents you really have!

【推荐3】I hesitated when my friend suggested that we join the school’s new Tai Chi club. I used to think that tai chi was for the elderly. However, the first class changed my previous understanding of tai chi. A year later, I can say that tai chi has had a huge impact on me.

The first few tai chi classes were fun and easy, and the moves with descriptive names really caught my imagination, like “white crane spreading its wings” and “golden rooster standing on one leg.” When I asked my coach where these interesting names came from, he told me about the history of tai chi. Zhang Sanfeng, a 13th-century Taoist, was said to have invented tai chi after drawing inspiration from a fight between a snake and a bird. However, nowadays people tend to believe that Chen Wangting, a 17th-century master of Chinese martial arts, developed tai chi based on martial arts skills.

After the first few basic tai chi lessons, I found myself bored and aching from doing the same slow moves over and over again. Fortunately, my coach taught me how to relax my muscles and focus on peace of mind during ever, day practice. With these requirements of tai chi in mind, I found to my satisfaction that my balance and flexibility slowly improved, that I was able to do more difficult moves, and that my love for tai chi returned stronger than ever.

Meanwhile, I started to explore the ancient Chinese culture behind tai chi. I discovered that tai chi is deeply rooted in the Chinese philosophy of yin and yang, which are believed to form the the unity of opposite. Neither can exist independent of the other. The practice of tai chi aims to keep the balance of yin and yang in the body through opposite movements: forwards and backwards, up and down, left and right, breathing in and breathing out. Ultimately, tai chi brings about a state of physical balance and mental peace.

The experience of a year of tai chi has affected my everyday life positively. I sleep more soundly at night, and feel more energetic during the day. I feel happier and more confident. Tai chi has taught me to relax my mind, enabling me to stay calm in stressful situations. I am sure I will continue to practise tai chi and enjoy the benefits it has brought me.