It is bad to have food stuck between your teeth for long periods of time. This is because food attracts germs; germs produce acid, and acid hurts your teeth and gums. Flossing (使用牙线) helps to remove the food that gets stuck between your teeth. This explains why flossing helps to keep your mouth healthy, but some doctors say that flossing can also be good for your heart.

    It may seem strange that something you do for your teeth can have any effect on your heart. Doctors have come up with a few ideas about how flossing works to keep your heart healthy. One idea is that the germs that hurt your teeth can leave the mouth and travel into your blood.Germs that get into the blood can then attack your heart. Another idea is based on the fact that when there are too many germs in your mouth, the body tries to fight against there germs. For some reason, the way the body fights these mouth germs may end up weakening the heart overtime.

    Not every doctor agrees about these ideas. Some doctors think that the link between good flossing habits and good heart health is only a coincidence. The incidence (发生率) of two or more events is completely random, as they do not admit of any reliable cause and effect relationship between them. For example, every time I wash my car, it rains. This does not mean that when I wash my car, I somehow change the weather. This is only a coincidence. Similarly, some doctors think that people who have bad flossing habits just happen to also have heart problems, and people who have good flossing habits just happen to have healthy hearts.

    The theory that flossing your teeth helps to keep your heart healthy might not be true. But every doctor agrees that flossing is a great way to keep your teeth healthy. So even if flossing does not help your heart, it is true to help your teeth. This is enough of a reason for everyone to floss their teeth every day.

    What's your dream vacation? Watching wildlife in Kenya? Boating down the Amazon? Sunbathing in Malaysia? New chances are opening up all the time to explore the world.So we visit travel agents, compare packages and prices, and pay our money.

    We know what our vacation costs us.But do we know what it might cost someone else?It's true that many poorer countries now depend on tourism for foreign income.Unfortunately,though.tourism often harms the local people more than it helps them

    It might cost their homes and lands.In Myanmar.5.200 people were forced to leave their homes among the pagodas(佛塔）in Bagan so that tourists could visit the pagodas.

    Tourism might also cost the local people their livelihood（生计）and dignity（尊严）.Local workers often find only jobs with slim salaries in the tourist industry.And most of the profits（利润）do not help the local economy. Instead,profits return to the tour operators in wealthier countries,When the Maasai people in Tanzania were driven（驱赶）from their lands,some moved to city slums.Others now make a little money selling souvenirs or posing(摆姿势）for photos.

    Problems like these were observed more than 20 years ago.But now some non-government organizations,tour operators and local governments are working together to begin correcting them.Tourists,too,are putting on the pressure.

    The result is responsible tourism,or ethical tourism.Ethical tourism has people at its heart.New international agreements and codes of conduct（行为准则）can help protect the people's lands homes,economies and cultures.The beginnings are small,though,and the problems are complex.

    But take heart. The good news is that everyone,including us,can play a part to help the local people in the places we visit Tour operators and companies can help by making sure that local people work in good conditions and earn reasonable wages.

    They can make it a point to use only locally owned hotel restaurants and guide services.They can share profits fairly to help the local economy And they can involve the local people in planning and managing tourism.

    What can tourists do? First, we can ask tour companies to provide information about the conditions of local citizens.We can then make our choices and tell them why. And while we're abroad, we can: Buy local foods and products, not imported ones.

    Pay a fair price for goods and services and not bargain for the cheapest price.

    Avoid flaunting wealth.

    Ask before talking photographs of people.They are not just part of the landscape!

    Let's enjoy our vacation and make sure others do,too.

    Can you imagine a world without music? Studies show that public schools across the country are cutting back on music classes to save money. Worse, some schools have never had music classes to begin with. But without them, students' academic growth and emotional health could suffer. In fact, music classes are necessary for all students in schools.

    Recent studies by Brown University have shown that students who received music education classes were better in math and reading skills than those without music classes. Another study by The College Board found that students taking music and art classes got higher points. Students' academic success seems to depend on their taking part in music education.

    Music programs in public schools also help to add to a student's sense of pride and self­confidence. Teens today have too many learning tasks. Besides, they have family problems, self­confidence problems, relationship troubles, and choices about drugs and alcohol. All of these can stop academic success, but music education can help. A study by The Texas Commission on Drug and Alcohol Abuse found that students who took part in school music programs were less likely to turn to drugs. Music programs encourage students to work together to produce an excellent performance.

    Music crosses language, class, cultural and political boundaries (界限). Music allows students from different countries to connect. For example, at a school talent show, a new Japanese student played a piano duet (二重奏) with an American classmate. Although they could not communicate verbally (口头上), they were able to read the music in order to play the duet. Two students from different cultures worked as a team with self­confidence and common purpose through music.

    The gift of music is priceless. We need to be sure to have necessary music classes for all students. The world is losing its music, and putting music into schools is the first step to get it back.

    Teens and younger children are reading a lot less for fun, according to a Common Sense Media report published Monday.

    While the decline over the past decade is steep for teen readers, some data in the report shows that reading remains a big part of many children's lives, and indicates how parents might help encourage more reading.

    According to the report's key findings, “the proportion (比例) who say they 'hardly ever' read for fun has gone from 8 percent of 13-year-olds and 9 percent of 17-year-olds in 1984 to 22 percent and 27 percent respectively today.”

    The report data shows that pleasure reading levels for younger children, ages 2-8, remain largely the same. But the amount of time spent in reading each session has declined, from closer to an hour or more to closer to a half hour per session.

    When it comes to technology and reading, the report does little to counsel(建议) parents looking for data about the effect of e-readers and tablets on reading. It does point out that many parents still limit electronic reading, mainly due to concerns about increased screen time.

    The most hopeful data shared in the report shows clear evidence of parents serving as examples and important guides for their kids when it comes to reading. Data shows that kids and teens who do read frequently, compared to infrequent readers, have more books in the home, more books purchased for them, parents who read more often, and parents who set aside time for them to read.

    As the end of school approaches, and school vacation reading lists loom(逼近) ahead, parents might take this chance to step in and make their own summer reading list and plan a family trip to the library or bookstore.

Kindle E-reader, 8th generation

    Free Touchscreen Display

    Price: $79. 99

    ● Thin and light for one-handed reading

    New Kindle is 11% thinner and 16% lighter than the previous generation Kindle, making it easy and comfortable to hold in one hand.

    ● Read like real Paper

    Kindle creates text similar to what you see in a physical book. The blacks and whites on the screen are uniform, improving text and image quality.

    ●Long-life battery

    Kindle doesn't need power to show a page of text, allowing you to read for weeks on a single charge.

    ● Thousands of books, no distraction (分心)

    Kindle is designed to be an e-reader. It satisfies your love of reading without interruptions like e-mails and phone calls.

    ●Look it up without leaving your page

    Smart Lookup combines entries from The New Oxford American Dictionary with information from Wikipedia, so you can know meanings, characters and more without losing your place.

    ●Adjust your text size

    Choose from eight text sizes to prevent tired eyes, so you can keep reading longer.

    Customer reviews:

    ※ Damon, May 21, 2019

    The price is great with an extra $ 20 off and this new Kindle is smaller in my hands than my old one. I was sad to lose my old Kindle, but this one is terrific.

    ※ Jason, January 26, 2019

    I miss the original Kindlers size—this one is too small. Also, the screen is overly sensitive and things pop up (弹出) and the battery doesn't last as long as the original Kindle. But my biggest disappointment is that this Kindle doesn't allow you to transfer everything from the original Kindle、so I lost all of the information from my old one. Overall, disappointing.

    ※ Susan, November 17, 2018

    I had the original Kindle, and the battery lasted for weeks. This battery only seems to last a few days, however. The other problem I have with this version of the Kindle is the touch screen. It is annoying when you are reading and start turning the wrong way. Sometimes, it's hard to get the page to turn the way you'd like it to.

Three grade 11 students from Harbour View High School, Canada, wanted to convey their message of fighting climate change to a younger audience. So, they wrote a children's book named Keeping It Cool as part of a project.

Upon receiving their first order of 12 copies, Claire Malco, the illustrator of the book, vividly recalls the moment when the realization struck. "I just sat there with my mouth open and was like, wow, this is actually happening," Malco told CBC News.

Coauthored by Joanna Jackson and Olivia Jordan, the book employs age-appropriate analogies (类比), coupled with vibrant illustrations, to promote actions kids can take against climate change. To explain the concept of the atmosphere, for example, the young authors drew a bubble(气泡) around Earth throughout the story. They also call for actions, such as planting trees and vegetable gardens – explaining how plants absorb CO2 from the "bubble" atmosphere just like a vacuum cleaner (真空吸尘器). The book also tells kids how they can avoid polluting the bubble by trying to walk, bike or scoot instead of taking a car or bus.

"The entire second half of the book is just things kids can do without needing their parents' support … We wanted it to be something that every kid could finish," Jordan explained to CBC News.

On Earth Day, the students visited a local elementary school where they read their stories and facilitated discussions about the text with every grade 5 class. They spread awareness that, regardless of age, anybody can help make a positive impact on Earth's climate."Educating students was the intention when writing this book. Having the opportunity to present to 10 different classes helped us gain insight on how to better our presentation and content, as well as see the impact this book will have on students," the students told Our Canada Project.