Using too much water or throwing rubbish into our rivers are clear ways that humans can put our water supply in danger , but we also affect our water supply in less obvious ways. You may wonder how paving(铺砌) a road can lead to less useable fresh water. A major part of the water we use every day is groundwater. Groundwater does not come from lakes or rivers. It comes from underground. The more roads and parking lots we pave ，the less water can flow into the ground to become groundwater.

    Human activity is not responsible for all water shortages(短缺). Drier climates are of course more likely to have droughts(干旱) than areas with more rainfall, but in any case, good management can help to make sure there is enough water to meet our basic needs.

    Thinking about the way we use water every day can make a big difference, too In the United States , a family of four can use 1.5 tons of water a day! This shows how much we depend on water to live, but there's a lot we can do to lower the number.

    You can take steps to save water in your home. To start with use the same glass for your drinking water all day. Wash it only once a day. Run your dishwasher (洗碗机)only when it is full 。Help your parents fix any leaks in your home. You can even help to keep our water supply clean by recycling batteries instead of throwing them away.

    A fourth-grade teacher allowed one of her students to shave her head in the schoolyard, after bullies（仗势欺人者）teased him about his own short buzz cut（短寸头发型）. Tori Nelson got the idea after noticing that Matthew Finney, a shy boy from her homeroom at Winlock Miller Elementary School in Washington state, was standing outside his classroom crying and wearing a winter hat.

    Ms. Nelson could see the back of his neck had been shaved, and since Matthew usually had very thick brown curly hair, she realized that he'd had a haircut over the weekend. She asked him what was wrong, and he said he'd gotten a buzz cut for the summer. But this morning, a fifth grader on the bus made fun of him, and he didn't want to come to class and get teased by other kids. Ms Nelson tried to convince Matthew to come inside, but since school rules prohibit kids from wearing hats indoors he refused – explaining that he was afraid of showing his haircut to the other children in case they also made fun of him.

    Finally I said: "If you take off your hat and come to class, I'll let you give me a buzz cut, too," 'Ms Nelson told Yahoo Parenting. I figured it's just hair, and mine is already short anyway. I might as well get it shorter in time for the warm weather.'

    Matthew excitedly took her up on the offer, and Ms Nelson and another teacher gathered all the fourth graders together during break time. A school employee brought in scissors, which Matthew used to the cheers of his classmates, excitedly watching as his teacher's hair fell away onto the ground in the schoolyard.

    'It was a lot of fun for the kids, and it helped Matthew feel better about himself,' said Ms Nelson.' You have to do what it takes to reach children. Teaching isn't just about reading and writing, it's about self-esteem and accepting differences.'

    Want to choose an English novel to enjoy? Here are four popular books sold on the website of Amazon, with formats and editions of kindle, hardcover, or paperback.

    Thomas Cheatham had planned to study Latin during his time at Hebron High School in Texas. But when he learned that the school district was going to offer a Mandarin(普通话) class, he quickly changed his mind.

    "I thought Mandarin would be more beneficial than Latin," said Cheatham, who is now in his second year of studying the language.

    He speaks Mandarin to order food at Chinese restaurants and can read social media posts from his Chinese-speaking friends. While it's a difficult language to master, the high school junior, who plans to study computer engineering, thinks it will be important for his career. "Chinese is a good language to know, especially with China becoming a growing power," he said.

    Many experts agree that proficiency(熟练) in a language spoken by a billion people worldwide will give American students an edge in the global economy.

    "People are looking at China as our next economic competitor, and interest in Mandarin is growing fast," said Marty Abbott, director of the American Council(议会) on the Teaching of Foreign Languages. "We're seeing it in all parts of the country."

    Abbott predicts that as many as 100,000 students are now studying Mandarin in public and private schools throughout the US. She said the US government has designated (指定) Mandarin as an "important needs" language and provides professional development programs for teachers. "Our government wants to increase our language ability for national security and economic competitiveness," Abbott added.

    At the same time, the Chinese government is spreading knowledge of the Chinese language and culture through Confucius Institutes set up in many US states. For example, the Confucius Institute at the University of Texas in Dallas has been the home of a Confucius Institute for 10 years. It sponsors Confucius Classrooms at 21 local public and private schools, where tens of thousands of students are learning Mandarin.

    A new study by the British government has discovered the mental well-being of the country's teenage girls has worsened.

    The survey, which included 30,000 14-year-old students, showed 37 percent of the girls with psychological stress, rising from 34 percent in 2010. British boys' stress level was actually seen to fall over the same period, from 17 percent to 15 percent. The report's authors pointed out the "arrival of the social media age" could be a major contributing factor for increasing stress among teenage British girls.

    "The adolescent years are a time of rapid physical, cognitive and emotional development," Pam Ramsden, a lecturer in psychology at the University of Bradford in the United Kingdom, wrote in a recent blog post. "Teenagers interact with people in order to learn how to become competent adults. In the past, they would engage with parents, teachers and other adults in their community as well as extended family members and friends. Now we can also add social media to that list of social and emotional development." Throughout adolescence, girls and boys develop characteristics like confidence and self-control. Since teenage brains have not completely developed, teens don't have the cognitive awareness to keep from posting inappropriate content. Furthermore, this content can easily be circulated far and wide with disastrous implications.

    "Social media can also feed into girls' insecurities about their appearance," Ramsden said. These sites are often filled with images of people with body type unattainable to the normal person. However, these images and the messages tied to them creep into social standards.

    "Social media allows girls to make comparisons among friends as well as celebrities and then provides them with 'solutions' such as extreme dieting tips and workouts to reach their goals," Ramsden said. "Concerns about body image can negatively impact their quality of life preventing them from having healthy relationships and taking up time that could be better spent developing other aspects of their personalities."

    The United States estimates that about one out of every 10 people on the planet today is at least 60 years old. By 2050, it's projected to be one out of 5. This means that not only will there be more old people, but there will be relatively fewer young people to support them.

    Professor Richard Lee of the University of California at Berkeley says this aging of the world has a great effect on economics. "Population aging increases the concentration of population in the older ages and therefore it is expensive," he said.

    Aging populations consume (消耗) more and produce less. With more people living longer, it could gel expensive. But Mr. Lee says with continuing increases in worker productivity and wise planning, it can be manageable.

    Societies have different methods for caring for the elderly，but each carries a cost Generally, there are three types of support Seniors can live off the wealth they gained when they were younger. They can rely on their family to take care of them, or they can rely on the movement.

    In industrialized nations, governments created publicly-funded (公共资助的) support systems. These worked relatively well until recent years, when aging population growth in places like the United States and Western Europe began to gradually weaken the systems' finances(资金). These nations now face some tough choices. Mr. Lee says the elderly in some of these countries must either receive less money, retire later or increase taxes to make the system continuable.

    Most developing nations haven't built this type of government-funded support, but have instead relied on families to care for their elderly. These nations also generally have a much younger population, which means their situation is not as urgent as more developed nations. But Mr. Lee says that doesn't mean they can pay no attention to the issue. "Third World countries should give very careful thought to this process, to population aging and how it may affect their economies — now, before population aging even becomes a problem," he explained.