The arts, especially music, should be part of every school's lessons at every grade level. Students would be much smarter if they had musical experience. They could improve their classroom skills, like paying attention and following directions. People develop all these skills when they learn music. Making music also lets children use their imagination. It provides students with a chance to try out their own ideas.

    Music not only makes children better students, but also gives them something positive to do. In a music program, children can be part of a band instead of joining a gang(团伙). Parents can enjoy listening to their children's music instead of seeing them glued to a computer or TV screen. In a school band, students get to be part of a team. They can get along well with old friends and make new friends through music.

    Music builds self-confidence, too. It gives children a sense of achievement and success. Making music is something for them to be proud of. And it lets kids practice performing in front of an audience. Music gives children an opportunity for self-expression, and that helps develop their self-confidence.

    Once again, music is important because it can make children better students, give them something positive to do, and build their character. That is why music should be offered in every single grade in every school.

    We may think we're a culture that gets rid of our worn technology at the first sight of something shiny and new, but a new study shows that we keep using our old devices（装置）well after they go out of style. That's bad news for the environment – and our wallets – as these outdated devices consume much more energy than the news ones that do the same things.

    To figure out how much power these devices are using, Callie Babbitt and her colleagues at the Rochester Institute of Technology in New York tracked the environmental costs for each product throughout its life – from when its minerals are mined to when we stop using the device. This method provided a readout for how home energy use has evolved since the early 1990s. Devices were grouped by generation. Desktop computers, basic mobile phones, and box-set TVs defined 1992. Digital cameras arrived on the scene in 1997. And MP3 players, smart phones, and LCD TVs entered homes in 2002, before tablets and e-readers showed up in 2007.

    As we accumulated more devices, however, we didn't throw out our old ones. "The living-room television is replaced and gets planted in the kids' room, and suddenly one day, you have a TV in every room of the house," said one researcher. The average number of electronic devices rose from four per household in 1992 to 13 in 2007. We're not just keeping these old devices – we continue to use them. According to the analysis of Babbitt's team, old desktop monitors and box TVs with cathode ray tubes are the worst devices with their energy consumption and contribution to greenhouse gas emissions（排放）more than doubling during the 1992 to 2007 window.

    So what's the solution? The team's date only went up to 2007, but the researchers also explored what would happen if consumers replaced old products with new electronics that serve more than one function, such as a tablet for word processing and TV viewing. They found that more on-demand environment viewing on tablets instead of TVs and desktop computers could cut energy consumption by 44%.

    MOOC, a massive(大规模的) open online course, aims at providing interactive discussion and open access via the web. In addition to traditional course materials such as videos, readings, and problem sets, MOOCs provide interactive user forums (论坛) that help build a community for the students, professors, and teaching assistants.

    MOOCs first made waves in the fall of 2011, when Professor Sebastian Thrun from Stanford University opened his graduate-level artificial intelligence course up to any student anywhere, and 160,000 students in more than 190 countries signed up. This new kind of online classes is shaking up the higher education world in many ways. Since the courses can be taken by hundreds of thousands of students at the same time, the number of universities might decrease greatly. Professor Thrun has even imagined a future in which there will only need to be 10 universities in the world. Perhaps the most impressive thing about MOOCs, many of which are being taught by professors at prestigious (声誉高的) universities, is that they're free. This is certainly good news for cash-strapped students.

    There is a lot of excitement and fear about MOOCs. While some say free online courses are a great way to increase the enrollment (注册) of students who are lack of resources, some critics (批评者) have said that MOOCs encourage an unrealistic one-size-fits-all model of higher education and that there is no replacement for true dialogues between professors and their students. After all, a brain is not a computer. We are not blank hard drives waiting to be filled with data. People learn from people they love and remember the things that arouse emotion. Some critics worry that online students will miss out on the social aspects of college.

    People have grown taller over the last century, with South Korean women shooting up by more than 20cm on average, and Iranian men gaining 16.5cm. A global study looked at the average height of 18-year-olds in 200 countries 1914 and 2014. The results show that while Swedes were the tallest people in the world in 1914, Dutch men have risen from l2th place to claim top spot with an average height of 182.5cm. Larvian women, meanwhile, rose from 28th place in 1914 to become the tallest in the world a century later, with an average height of 169.8cm. James Bentham, a co-author of the research says the global trend is likely but once you average over whole populations, genetics plays a less key role," he added.

    But while height has increased around the world, the trend in many countries of north and sub-Saharan Africa causes concern, says Elio Riboli of Imperial College. While height increased in Uganda and Niger during the early 20th century, the trend has reversed in recent years, with height decreasing among 18-year-olds.

    "One reason for these decreases in height is the economic situation in the 1980s," said Professor Alexander. The nutritional and health problems that followed the policy of structural adjustment, he says, led to many children and teenagers failing to reach their full potential in terms of height.

    Bentham believes the global trend of increasing height has important implications. "How tall we are now is strongly influenced by the environment we grew up in," he said. "If we give children the best possible start in life now, they will be healthier and more productive for decades to come."

    On August 5 just after 7.30 pm, Mike Estepa suffered a massive heart attack. The crazy cyclist was 40 kilometres into his Sunday ride when he stopped by the side of the road to text his family saying he'd be home in about 30 minutes. Moments later, he was lying in the ditch, unconscious.

    Larissa Arthur was driving back to Calgary from a hike in Field, B. C. with a friend. It was a warm and sunny day, and the two were chatting when a flush of yellow caught Arthur's eyes. She immediately pulled off the road.

    As Arthur approached the figure, she feared the worst: Estepa was covered in ants and exhibited no signs of life. There was no pulse and he wasn't breathing." says Arthur. A bystander called 911 and Arthur, a registered nurse, started chest compressions. She and two other drivers took turns carrying out CPR for the next 15 minutes before medical teams arrived and whisked Estepa away.

    Two days later, when Estepa woke up in the hospital, he was shocked to learn he had gone into cardiac arrest (心脏骤停). How did this happen, and, why was he lucky enough to have survived? He was full of gratitude and needed to speak with the woman who had saved him, whom he named his "angel".

    "It was emotional," says Arthur of her meeting with Estepa a few weeks later. Saving his life had extra importance for her: the bike she was returning from that day was one of 100 she's planned to honour her father, who died in 2017 after he fell during a hike that Arthur was meant to be on. "I couldn't save my father's life." Arthur says, "but this was a chance for me to save someone."

This winter, the U. S. state of California received unusually large amounts of rain and snow. Now, people worry that some areas will flood as the snow in the Sierra Nevada Mountains melts (融化).

Ron Caetano lives about half-way between the cities of Los Angeles and San Francisco. He is preparing to leave in case his community, called the Island District, floods.

More than 100 years ago, the Island District area was under a large lake named Tulare Lake. At one time, Tulare Lake was the largest freshwater lake west of the Mississippi River. But reservoirs (水库) and watering systems for agriculture caused it to disappear. However, in very rainy years, farmland can still get covered with water.

Experts say reservoirs near the area will likely receive three times more water than they can hold this year. That means officials must increase the amount of water they release (释放) from the reservoirs. If too much water is released, the area might flood.

The Island District has organized a community network to help prepare for floods. People are placing sandbags close to elderly neighbors' houses to block possible flooding. And they are looking at reports from water officials, county officials, and from each other.

California has had very dry weather in recent years. Both cities and farm communities acclaimed this year's winter rains. If the weather gets warmer slowly, the snow will not melt quickly and there may be little or no flooding. But if the weather gets hot quickly, that will bring trouble from too much melting snow.

Officials announced plans to close parts of Yosemite National Park because of threats of flooding. The park is about 270 kilometers east of San Francisco in the Sierra Nevada Mountains.

Nicholas Pinter is with the University of California, Davis Center for Watershed Sciences. He said the lake's size has always changed because of California's weather. He described the surrounding area this way. "It has been an engineering problem all along," he said. "This is a bathtub (浴缸) with no way out."