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.

In the latest beauty craze(狂热)sweeping social media in China，women--and even some men--are boasting that they are paper thin，by posting photographs of their waists behind a vertical(垂直)piece of A4 paper．To qualify，the waist must be entirely hidden by the paper．A piece of A4 paper is 8.3 by ll.7 inches，roughly the size of a sheet of American letter paper．

    With the A4 Waist，the trend is attracting hundreds of photographs and thousands of comments on Weibo and other social media networks like Weixin or WeChat．Being abnormally thin is a widespread standard of beauty for women，one that has been criticized as an unhealthy ideal of female attractiveness．

    The tiny waist has a long tradition in China，going back at least to King Ling of Chu，who ruled from 540 to 529 B．C．Many in China know the passage from the Book of Han，the history of the Western Han Dynasty：“The King of Chu loved a narrow waist．Many people at court starved to death．

    Several commentators have found the A4 trend disturbing．In a telephone interview，He Xiaobin，senior fashion features editor at the Chinese edition of GQ magazine，said，“I find it completely stupid．Everybody has a different frame and body shape．Using a single size to define all human beings and thinking you have created a new standard is foolish．''The A4 waist challenge annoyed him，saying that it allows certain people to gain bragging rights，while leaving others in depression．

    Luckily，some who do not qualify are turning to humor for comfort．Can they substitute a different paper size，such as A3，which is 11.7 inches across Or measure a body part besides the waist?

阅读下列短文，从每题所给的四个选项（A、B、C和D）中，选出最佳选项。

    Are you sometimes a little tired and sleepy in the early afternoon? Many people feel this way after lunch. They may think that eating lunch is the cause of the sleepiness. Or, in summer, they may think it is the heat. However, the real reason lies inside their bodies. At that time—about eight hours after you wake up—your body temperature goes down. This is what makes you slow down and feel sleepy. Scientists have tested sleep habits in experiments where there was no night or day. The people in these experiments almost always followed a similar sleeping pattern. They slept for one long period and then for one short period about eight hours later.

    In many parts of the world, people take naps (小睡) in the middle of the day. This is especially true in warmer climates, where the heat makes work difficult in the early afternoon. Researchers are now saying that naps are good for everyone in any climate. A daily nap gives one a more rested body and mind and therefore is good for health in general. In countries where naps are traditional, people often suffer less from problems such as heart disease. Many working people, unfortunately, have no time to take naps. Though doctors may advise taking naps, employers do not allow it! If you do have the chance, however, here are a few tips about making the most of your nap. Remember that the best time to take a nap is about eight hours after you get up. A short sleep too late in the day may only make you feel more tired and sleepy afterward. This can also happen if you sleep for too long. If you do not have enough time, try a short nap—even ten minutes of sleep can be helpful.

    One day an old woman was travelling alone in the mountains. Suddenly she saw something shining in the stream（溪流）. When she came close, she found it was a precious（宝贵的）stone. She put the stone into her bag and went on with her trip.

    The next day the old woman met a young man, who was also a traveler in the mountains. The young man looked very hungry, so the old woman opened her bag to share her food. The hungry traveler saw the precious stone and asked carefully, "The stone is beautiful. Would you like to give it to me?"

    "Sure. Why not?" the woman said, and handed the stone to him.

    The young man left happily with the stone. He knew it was worth enough to give him security for a lifetime. But a few days later he came back to return the stone to the woman.

    "I've been thinking." he said. "I know how valuable the stone is, but I give it back and hope that you can give me something even more precious. Give me what you have in your bag."

    The woman opened her bag. It was almost empty. She looked at the young man and smiled, "I have nothing special in my bag, but I do have something precious—the joy of giving!"

    The young man felt ashamed (惭愧的）and left silently.

    The market for products designed specifically for older adults could reach $30 billion by next year, and startups (初创公司) want in on the action. What they sometimes lack is feedback from the people who they hope will use their products. So Brookdale, the country's largest owner of retirement communication, has been inviting a few select entrepreneurs just to move in for a few days, show off their products and hear what the residents have to say.

    That's what brought Dayle Rodriguez, 28, all the way from England to the dining room of Brookdale South Bay in Torrance, California. Rodriguez is the community and marketing manager for a company called Sentab. The startup's product, Sentab TV, enables older adults who may not be comfortable with computers to access email, video chat and social media using just their televisions and a remote control.

    "It's nothing new, it's nothing too complicated and it's natural because lots of people have TV remotes." says Rodriguez.

    But none of that is the topic of conversation in the Brookdale dining room. Instead, Rodriguez solicits residents' advice on what he should get on his cheeseburger and how he should spend the afternoon. Playing cards was on the agenda, as well as learning to play mahjong(麻将).

    Rodriguez says it's important that residents here don't feel like he's selling them something. "I've had more feedback in a passive approach." he says. "Playing pool, playing cards, having dinner, having lunch, all work better than going through a survey of questions. When they get to know me and to trust me, knowing for sure I'm not selling them something—there'll be more honest feedback from them."

    Rodriguez is just the seventh entrepreneur to move into one of Brookdale's 1,100 senior living communities. Other new products in the program have included a kind of full-body blow dryer and specially designed clothing that allows people with disabilities to dress and undress themselves.

    "First and foremost, the residents love it." says Smith. "It also provides Brookdale the opportunity to learn about and experience new technologies quickly and inexpensively and to make sure that we understand what residents want and need."

    Mary Lou Busch, 93, agreed to try the Sentab system. She tells Rodriguez that it might be good for someone, but not for her.

    "I have the computer and FaceTime, which I talk with my family on." she explains. She also has an iPad and a smart phone. "So I do pretty much everything I need to do."

    Rodriguez takes it pretty well.

    "I'm not going to lie to you, I would've liked a more positive response." he says. But "if people don't need it or want it, it's up to us to change, adapt it or make it more useful."

    To be fair, if Rodriguez had wanted feedback from some more technophobic (害怕技术的) seniors, he might have ended up in the wrong Brookdale community. This one is located in the heart of Southern California's aerospace corridor. Many residents have backgrounds in engineering, business and academic circles.

    But Rodriguez says he's still learning something important by moving into this Brookdale community: "People are more tech-skilled than we thought."

    And besides, where else would he learn to play mahjong?