Disposing(处理) of waste has been a problem since humans started producing it. As more and more people choose to live close together in cities, the waste-disposal problem becomes increasingly difficult.

    During the eighteenth century, it was usual for several neighboring towns to get together to select a faraway spot as a dumpsite. Residents or trash haulers(垃圾托运者) would transport household rubbish, rotted wood, and old possessions to the site. Periodically(定期的) some of the trash was burned and the rest was buried. The unpleasant sights and smells caused no problem because nobody lived close by.

    Factories, mills, and other industrial sites also had waste to be disposed of. Those located on rivers often just dumped the unwanted remains into the water. Others built huge burners with chimneys to deal with the problem.

    Several facts make these choices unacceptable to modern society. The first problem is space. Dumps, which are now called landfills, are most needed in heavily populated areas. Such areas rarely have empty land suitable for this purpose. Property is either too expensive or too close to residential(住宅区的)neighborhoods. Long-distance trash hauling has been a common practice, but once farm areas are refusing to accept rubbish from elsewhere, cheap land within trucking distance of major city areas is almost nonexistent.

    Awareness of pollution dangers has resulted in more strict rules of waste disposal. Pollution of rivers, ground water, land and air is a price people can no longer pay to get rid of waste. The amount of waste, however, continues to grow.

    Recycling efforts have become commonplace, and many towns require their people to take part. Even the most efficient recycling programs, however, can hope to deal with only about 50 percent of a city's reusable waste.

    After a confirmed rabies(狂犬病) case in Parke County, Indiana, experts are urging caution if you find a bat(蝙蝠) in your home or office.

    “If you try to kill a bat, you are more likely to get bitten,” said Joy O'Keefe, assistant professor of biology and director of Indiana State University's Centre for Bat Research, Outreach and Conservation. “Most bats people find in their houses are healthy and are not going to bite them and give them rabies.” But they could be a federally endangered species, such as the Indiana Bat, which is found in this area.

    So if you spot a bat in your home or office, don't kill it or touch it with bare hands, O'Keefe said. Instead, put on a pair of heavy gloves and gently move it into a box or bucket. Once contained, the bat can be removed outside.

    “If it's a healthy bat, it'll fly away eventually,” O'Keefe said. “If it doesn't move or seem to be healthy, you can take it to the health department to be tested.”

    This is the time of year when bats move from their summer resting sites to their winter resting sites, O'Keefe said.

    “We get calls every year during the first month of school year from people finding bats in the university's buildings,” said O'Keefe.

    Bats are a great help to people, as every night they can eat up to their entire body weight of insects. Bats, however, are facing great threats from epidemics(流行性疾病), habitat destruction and other things.

    “The best way the average person can help bats is by understanding them and by telling other people how awesome bats are and what bats do for us,” O' Keefe said. “Hopefully, it will make people think that if there's a bat in their house, they should try to get it out but not kill it. That would be really positive for bats—to not have people be one of their major threats.”

    You're out to dinner. The food is delicious and the service is fine. You decide to leave a big fat tip. Why? The answer may not be as simple as you think.

    Tipping, psychologists have found, is not just about service. Instead, studies have shown that tipping can be affected by psychological reactions to a series of different factors from the waiter's choice of words, to how they carry themselves while taking orders, to the bill's total. Even how much waiters remind customers of themselves can determine how much change they pocket by the end of the night.

    “Studies before have shown that mimicry(模仿) brings into positive feelings for the mimicker,” wrote Rick van Baaren, a social psychology professor. “These studies show that people who are being mimicked become more generous toward the person who mimics them.”

    So Rick van Baaren divided 59 waiters into two groups. He requested that half serve with a phrase such as. “ Coming up !” Those in the other hall were instructed to repeat the orders and preferences back to the customers. Rick van Baaren then compared their take-home pay. 'The results were clear—it pays to mimic your customer. The copycat(模仿者) waiters earned almost double the amount of tips to the other group.

    Leonard Green and Joel Myerson, psychologists at Washington University in St. Louis, found the generosity of a tipper maybe limited by his bill. After research on the 1,000 tips left for waiters, cabdrivers, hair stylists, they found tip percentages in these three areas dropped as customers' bills went up. In fact, tip percentages appear to plateau(稳定期) when bills topped $100 and a bill for $200 made the worker gain no bigger percentage tip than a bill for $100.

    “That's also a point of tipping,” Green says. “You have to give a little extra to the cabdriver for being there to pick you up and something to the waiter for being there to serve you. If they weren't there, you'd never get any service. So part of the idea of a tip is for just being there.”

    Sandra Cisneros was born in Chicago in 1954 to a Mexican American family. As the only girl in a family of seven children, she often felt like she had “seven fathers,” because her six brothers, as well as her father, tried to control her. Feeling shy and unimportant, she retreated(躲避)into books. Despite her love of reading, she did not do well in elementary school because she was too shy to participate.

    In high school, with the encouragement of one particular teacher, Cisneros improved her grades and worked for the school literary magazine. Her father encouraged her to go to college because he thought it would be a good way for her to find a husband. Cisneros did attend college, but instead of searching for a husband, she found a teacher who helped her join the famous graduate writing program at the University of Iowa. At the university's Writers' Workshop, however, she felt lonely－a Mexican American from a poor neighborhood among students from wealthy families. The feeling of being so different helped Cisneros find her “creative voice”.

    “It was not until this moment when I considered myself truly different that my writing acquired a voice. I knew I was a Mexican woman, but I didn't think it had anything to do with why I felt so much imbalance in my life, but it had everything to do with it! That's when I decided I would write about something my classmates couldn't write about.”

    Cisneros published her first work, The House on Mango Street, when she was twenty-nine. The book talks about a young Mexican American girl growing up in a Spanish-speaking area in Chicago, much like the neighborhoods in which Cisneros lived as a child. The book won an award in 1985 and has been used in classes from high school to graduate school level. Since then, Cisneros has published several books of poetry, a children's book, and a short-story collection.

    The biggest challenge faced by travelers, especially those who like to have a backpacking trip is how to ensure a steady supply of clean clothes. Now, thanks to a great invention called Scrubba Wash Pack, that worry may be a thing of the past.

    The portable washing machine was invented by Ash Newland in 2010, while he was planning to climb Mt. Kilimanjaro. Struck by the limited packing space, he got inspiration from traditional washboards to create a bag that could be used to clean clothes. Then he quitted his career as a lawyer and focused on perfecting the bag's design. By 2012, the bag was ready for the public. It weighed only 180 grams and required very little storage space, making it perfect for anymore wishing to travel light.

    Not surprisingly, the bag which was worth 55 dollars was an instant hit with travelers, university students and even passengers. However, Newland was not satisfied. He still saw a disadvantage with his invention—dirty clothes had to be carried around in a separate bag! The recently introduced Scrubba Wash Pack solves that problem.

    In order to make the pack active, dirty clothes are placed inside the bag along with two or three liters of water. The bag is then shut tightly to ensure all air is squeezed out and the colors are massaged for a few minutes. After a quick wash, they are clean and ready to be dried. According to Newland, the pack can clean anything from jeans to smelly socks! What's even more amazing is that with a capacity to hold 13 liters of water, it can be used to wash more clothes at a time.

    The best part is that the 99-dollar pack that will be available for sale later this year, only weighs 300 grams and is completely foldable, making it easy to store when it's not in use. With the Scrubba Wash Pack, wandering through foreign cities searching for a washing shop, or paying for washing machines may soon be a thing of the past!

What makes preschoolers eat their vegetables? Raise their hand? Wait their turn? "Because I say so" is a comment that parents often repeat. But when it comes to getting kids to behave, a recent study by Duke University researchers suggests that the voice of adult authority isn't the only thing that matters. Around age three, fitting in with the group starts to count big too.

To understand what cause preschoolers to fall    in    line, the researchers conducted a test in a lab, where they invited 3.5-year-olds to help set up for a pretend tea party. Each of the 104 children was given a blue sticker (贴纸) to wear at the start of the study, and told that the people with that color sticker were part of the same team. Next the researchers watched as the children decided among different kinds of teas, snacks, cups and plates for the tea party, first on their own and then after listening to the choices of other team members.

Sometimes the other team members considered their choice as a matter of personal preference ("For my tea party today, I feel like using this snack.") Other times they presented it as a need shared by the whole group. ("For our tea parties today, we always use this kind of snack.")

After listening to the choices of others, most of the time the children stuck with their first choice. In other words, children who had said they felt like using, say, the cookie finally picked the cookie no matter what the other person said they were using. But 23% of the time the children changed their choice to accept someone else's. And when they did, they were more likely to go along with the other person when a choice was presented as a group need rather than just a personal preference. The finding held up even when the other person was another child, not an adult.