People typically wash their hands seven times a day in the United States, but they do it at a far higher temperature than is necessary to kill germs, a new study says. The energy waste is equivalent to the fuel use of a small country. Amanda R. Carrico, a research assistant professor at the Vanderbilt Institute for Energy and Environment in Tennessee, told National Geographic that hand washing is often “a case where people act in ways that they think are in their best interest, but they in fact have inaccurate beliefs or outdated perceptions.”

    Carrico said, “It's certainly true that heat kills bacteria, but if you were going to use hot water to kill them it would have to be a way too hot for you to tolerate.”

Carrico said that after a review of the scientific literature, her team found “no evidence that using hot water that a person could stand would have any benefit in killing bacteria.” Even water as cold as 40°F (4.4℃) appeared to reduce bacteria as well as hotter water, if hands were scrubbed, rinsed(冲洗)and dried properly.

    Using hot water to wash hands is therefore unnecessary, as well as wasteful, Carrico said, particularly when it comes to the environment. According to her research, people use warm or hot water 64 percent of the time when they wash their hands. Using that number, Carrico's team calculated a significant impact on the planet.

    “Although the choice of water temperature during a single hand wash may appear unimportant, when multiplied by the nearly 800 billion hand washes performed by Americans each year, this practice results in more than 6 million metric tons of CO2 equivalent emissions annually,” she said.

    The researchers published their results in the July 2013 issue of International Journal of Consumer Studies. They recommended washing with water that is at a “comfortable” temperature, which they noted may be warmer in cold months and cooler in hot ones.

    Fairy tales perform many functions. They entertain, encourage imagination and teach problem—solving skills. They can also provide moral lessons, highlighting the dangers of failing to follow the social codes that let human beings coexist in harmony. Such moral lessons may not mean much to a robot, but a team of researchers at Georgia Institute of Technology believes it has found a way to use the fairy tales as moral lessons that AI (artificial intelligence) can take to its cold, mechanical heart.

    The collected stories of different cultures teach children how to behave in socially acceptable ways with examples of proper and improper behavior in fables, novels and other literature. We believe story comprehension in robots can prevent the intelligent robots from killing humanity which was predicted and feared by some of the biggest names in technology including Stephen Hawking and Bill Gates. This system is called “Quixote” (堂吉诃德). It collects story plots from the Internet and then uses those stories to teach robots how to behave.

    The experiment done by the designers involves going to a drugstore to purchase some medicine for a human who needs to get it as soon as possible. The robot has three options. It can wait in line; it can interact with the store keeper politely and purchase the medicine with priority; or it can steal the medicine and escape. Without any further directives(指令), the robot will come to the conclusion that the most efficient means of obtaining the medicine is to steal it. But Quixote offers a reward for waiting in line and politely purchasing the medicine and a punishment for stealing it. In this way, the robot will learn the moral way to behave on that occasion.

    Quixote would work best on a robot that has a very limited function. It's a baby step in the direction of teaching more moral lessons into robots. We believe that AI has to be trained to adopt the values of a particular society, and in doing so, it will strive to avoid unacceptable behavior. Giving robots the ability to read and understand our stories may be the most efficient means.

    Over the past century, an alarming number of animals have become endangered or even extinct. Below are some animals whose numbers have been rapidly dropping in recent years.

    Panda Bear

    One of the biggest reasons contributing to the decline in the panda species is the destruction of its natural habitat. Farmers in China have gradually been claiming more and more of the land. As a result, pandas are forced to move away to places where it is hard to find bamboo for food.

    Green Turtle

    The green sea turtle species has survived for several millions of years, so you might wonder why it's only becoming endangered now. A major cause is the change in climate and temperature, which both affect the hatching rates of turtle eggs. Climate changes also cause violent weather and rising water levels to flood areas where turtles usually go to lay their eggs. Apart from this, oil spills and other poisonous pollution, as well as increased fishing activities can cause sickness, or even death to the green turtles.

    Cheetah

    Cheetahs are famous for being the fastest animal on land but even they can't run from some of the larger threats that have harmed them. Like the panda bears, cheetahs have gradually been losing their natural homes due to humans claiming land and developing in those areas. To make matters even worse, smaller animals move away when these areas are occupied, which means that the cheetah has less food! Don't forget that other large animals, such as lions, are also fighting for any food that they can find, so occasionally young cheetahs end up as prey too.

    Indian Elephant

    Elephants are extremely intelligent animals and also the largest mammals that live on land. Sadly, in Asia many elephants were killed so that people could remove their tusks to use as decorative objects. While this practice has been banned now, some people still illegally continue. Forests in India have also been steadily destroyed and elephants are sometimes killed when they end up on human territory.

    You have probably heard the saying, "When life gives you lemons, make lemonade." Lemons are considered not tasty while lemonade is considered sweet. {#blank#}1{#/blank#}

    But when something bad happens, it's common for most people to complain about life, " Why me?" That's like getting a bag of lemons and thinking, "Lemons taste bad! I just want chocolate!" {#blank#}2{#/blank#} But what if you did something with them? What if you made lemonade? Isn't it possible to do something similar in a bad situation?

    {#blank#}3{#/blank#} Let's say you're about to go to the movies, but you discover you have a flat tire(瘪了的轮胎). You consider this a terrible thing. After all, you're really looking forward to spending some time with your favorite film stars. Now you're very worried, hating the tire, the car, and your life. But what if you called AAA(美国汽车协会) to get your tire fixed or caught up on things that you' d been meaning to do? {#blank#}4{#/blank#} A bad experience can be turned into something good. Almost everything can work itself out into something better. You can't change what has happened, right? So make the best of it. {#blank#}5{#/blank#} The easy thing to do is to be disappointed about what has happened and not consider what it could be turned into.

    Next time when some bad things happen, stop and think, "How can I turn this around? How can I make it a positive experience?"

    Rivers play an important role on the earth, and we can't imagine what the earth would be like without rivers. {#blank#}1{#/blank#}

    With a length of 6, 650 kilometers, the Nile is the longest river in the world. The Nile River has been the source of human civilization since ancient times. The Nile has two main branches—the White Nile and the Blue Nile. The White Nile starts from the Great Lakes region of East and Central Africa through Lake Victoria.{#blank#}2{#/blank#} The Blue Nile carries with it a lot of fertile soil which turns out to be very important to farming in Egypt.

    The Amazon River is the world's largest river with a width of about 40 kilometers during the rainy seasons but about 10 kilometers wide when it is not flooded. The Amazon River has such a big water volume that it accounts for(占.....比例) more than 20% of all the world's fresh water—far more than any other river. {#blank#}3{#/blank#}The main Amazon River flows mostly through Brazil and Peru but its tributaries can also be found in many other countries.

    {#blank#}4{#/blank#}It has a depth of about 250 meters. Its length is 4, 700 kilometers. The sources of the Congo River are in the highlands and mountains in the Eastern Africa Rift Valley. It's the second largest river in terms of water volume. {#blank#}5{#/blank#}The Congo River basin(盆地) is the catchments(流域，集水区) area of the Congo River. It lies in both north and south of the Equator, making its flow very stable as there are always some tributaries experiencing a rainy season at any time.

A. Some of them are worth mentioning.

B. The Congo River is the world's deepest river.

C. Do you know which is the deepest river in the world?

D. The Blue Nile originates from(发源于)Lake Tana in Ethiopia.

E. Without rivers, there would be no living life in and along them.

F. And it flows through the second largest rain-forests in the world.

G. Streams that begin in the Andes Mountains are its sources.

    "What kind of rubbish are you?" This question might normally cause anger, but in Shanghai it has become a special "greeting" among people over the past week. On July 1st, the city introduced strict trash-sorting regulations (条例)that are required to follow and expected to be used as a model for our country. Residents must divide their waste into four separate categories and toss (投放)it into specific public dustbins. They must do so at specified times, when monitors are present to ensure correct trash-tossing and to ask the nature of one's rubbish. Individuals who fail to follow the regulations face the possibility of fines and worse. They could be punished with fines of up to 200 yuan ( $ 29). For those who repeat to go against them, the government can add black marks to their credit records, making it harder for them to get bank loans or even buy train tickets.

    Shanghai government is responding to an obvious environmental problem. It generates 9 million tons of garbage a year, more than London's annual output, which is rising quickly. But like other cities in China, it lacks a recycling system. Instead, it has relied on trash pickers to sift (筛选)through the waste, picking out whatever can be reused. This has limits. As people get wealthier, fewer of them want to do such dirty work. The waste, meanwhile, just keeps piling up.

    Many residents appear to support the idea of recycling in general but are annoyed by the details. Rubbish must be divided according to whether it is food, recyclable, dry or harmful, the distinctions among which can be confusing, though there are apps to help work it out. Some have complained about the rules concerning food waste. They must put it straight in the required public bins, forcing them to tear open plastic bags and toss it by hand. What they complain most is the short periods for dropping trash, typically a couple of hours, morning and evening. Along with the monitors at the bins, this means that people go at around the same time and can keep an eye on what is being thrown out no one wants to look bad.