Have you ever rubbed your hands together when they get cold? Why do we do that? We do that for friction. Friction happens when two things that aren't very smooth (光滑的) rub together to make heat energy. The faster you rub two things together, the more friction you can make. Let' s discover friction!

WHAT YOU'LL NEED:
★Soap                ★Water           ★Your hands
WHAT TO DO:
★Make sure your hands are dry.
★Rub your hands together until you feel the heat of your hands.
★Now, use soap and water to get your hands very slippery (滑的).
★Try to make friction happen while your hands are slippery.
★Please write down what has happened.
LET'S TALK!
    Friction is an energy that happens when two things rub together. When friction happens, it makes heat! When your hands are slippery, they won't make very much friction and your hands won't get so hot.
DID YOU KNOW?
★Friction happens when you stop your fast running bike.
★Ancient people made fires by rubbing two pieces of wood together. Friction happened though they didn't know it. ___  __?         Friction is everywhere. Have you ever noticed situations where friction is happening? If not, ask your parents to take you out in a car. If it is not hot, touch the tires (轮胎) of the car before and after a short drive to see how much warmer they get from friction.

阅读理解。

Hover Camera(无人相机)

    Wang Mengqiu, the inventor of Hover Camera, was born in Hangzhou in 1982. He once studied at Stanford University in the United States. He became famous overnight(一夜成名) because of the invention.

    Forget selfie sticks(自拍杆)! Compared to other cameras, Hover Camera has many advantages.

    *It can fly and stay in mid-air, track your face and even follow you to make sure it gets the perfect picture.

    *It can be controlled by using a smartphone(智能手机).

    *It records movements with a 13MP camera and takes 4K video.

    *It is the best choice for weddings, sports games and holidays.

    Mr. Wang also said: “The main design consideration is easy and safe to take for the users. It's very light and small. It can be folded(折叠) in two, so it can be easily put into a bag. When the power is low, it can land on the ground safely on its own.”

    It's reported that the company has raised $ 25 million to produce it. As it is still being tested(测试), Hover Camera can be bought later this year.

The price has not yet been decided. But a spokesman says the company hopes to sell it for less than $ 600.

    According to a new scientific research, we are rapidly going close to major climate change and the effects on the environment could be quite serious. Geographers predict that climate zones could completely disappear within the next eighty years. Where will crops be grown if this happens? When the climate changes a lot, polar regions will get colder and tropical regions will get even hotter. As a result, where will animals be forced to move on the earth?

    Climate changes like these could lead to the spread of diseases. Tropical storms and hurricanes(飓风) will not only increase but may also become stronger. If the changes come too quickly, animals and plants may not be able to adapt(适应) right away and could disappear from the earth.

    According to Science Daily, a new study predicts that, by the year 2100, many of today's familiar climates will be taken place by climate unknown in today's world. It is urgent that we reduce the risks of far-reaching results for the whole world. The planet itself has been showing signs of change. In 2004, a huge tsunami created by a major earthquake killed thousands in Sumatra and in 2008, thousands more died in China in another big earthquake. Egypt was hit in 2009 with a major earthquake and Haiti was destroyed seriously and became ruins in 2010 by another big earthquake.

    Not long ago, scientists discovered ice melting(融化) in west Antarctica(南极洲). This is very worrying because temperatures in this area have remained rather constant(不断的) and actually even lower at time. Melting occurs when temperatures increase and since temperatures have remained, the ice should not be melting. However, satellite data(数据) shows melting around west Antarctica.

    Within just the last few months, new reports from around the world have been coming in and most agree that our climate situation is much worse than previously expected. At this point, it doesn't matter what is causing it, but rather, what can be done about it. On the other hand, our world is getting more and more unstable(不稳定) every year. Natural disasters(灾难) are becoming more frequent(频繁的) and serious.

    However, other planets are experiencing global warming as well as our own and some scientists believe there may be some connections between these. No one knows anything for sure at this point because there is simply not enough data.

New App Helps People Remember Faces

    Large gatherings such as weddings and meetings can be socially Q flooded with people. Learning people's names only adds to the stress. A new facial-recognition app could come to the rescue, but experts suggest people should be careful while using it.

    The app, called SocialRecall, connects names with faces through smartphone cameras and facial recognition, avoiding the need for formal introductions. "It breaks down these social barriers we all have when meeting somebody, "says Barry Sandrew, who created the app and tested it at an event attended by about 1, 000 people.

    After receiving an invitation to download SocialRecall from an event organizer, the user is asked to take two selfies and sign in through social media. At the event, the app is active within a previously set geographical area. When a user points his or her phone camera at an attendee's face, the app identifies the person, displays the person's name, and links to his or her social media information. To protect Privacy, it recognizes only those who have agreed to use. And the app's creators say it automatically removes users' data after an event.

    Ann Cavoukian, a expert who runs the Privacy by Design Center of Excellence praises the app's creators for these protective measures. She added, however, that when people choose to share their personal information with the app, they should know that "there may be unexpected results down the road with that information being used in another situation that might come back to bite you."

    The start-up project has developed the app for people who suffer from prosopagnosia, or "face blindness, "a condition that prevents people from recognizing people they have met. To use this app, a person first receives an image of someone's face, from either the smartphone's camera or a photograph, and then tags it with a name. When the camera spots or recognizes that same face in real life, the previously entered information is displayed. The collected data are stored only on a user's phone, according to the team behind the app.