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    According to the World Health Organization (WHO), environmental pollution kills 1.7 million children under the age of five every year worldwide. The WHO warns that child deaths will increase greatly if pollution continues to worsen. Of all the environmental problems, air pollution is being called the most dangerous.

    Most of these deaths take place in developing countries. However, WHO environment and health chief Maria Neira tells that air pollution is a leveler between rich and poor. Everybody, she says, needs to breathe.

    “You can be a very rich child, your parents very rich, but living in a place, in a city, which is very polluted. Then there is very little you can do because we all need to breathe. Air pollution is everywhere.”

    Maria Neira says one of the most important ways to reduce air pollution is to produce cleaner fuels for cooking and heating.

    “Almost half of the world population is using dirty fuels for cooking, heating, and lighting at home. And, this is affecting very much mothers who are staying and cooking at home, but the children who are around mothers—they are exposed as well.”

    Cleaning up how the world cooks, heats and lights homes and other buildings is a big-picture goal.

    But what can every one of us do to limit our family to air pollution?

    The U.S. Environmental Protection Agency has the following suggestions:

    ● Avoid walking where there is a high volume of vehicle traffic.

    ● Equip homes with air filters and air conditioning units.

    ● Limit your time outside if you live in an area that issues warnings about air quality.

    ● Wear high-grade, rated face masks tightly to the face when air quality is poor.

    ● If you live or commute in a very polluted area, remove your clothes and wash immediately after entering your house.

    However, the WHO stresses that governments around the world need to take the lead on ensuring that children grow up in a clean environment.

    In 1969, humans landed on the moon for the first time. Now, many other countries want to go there as well. Why?

    The moon has a lot of minerals (矿物质) and other useful things. We want to find out if we can use them. The moon is our closest neighbor in space. We can use it as a rest station. Then, we can learn more about other planets far away in space.

    The moon is 3,474 kilometers in diameter (直径). It is about one-fourth the size of Earth. If Earth is the size of a basketball, the moon is the size of a tennis ball.

    The moon has much less gravity than Earth. If you can jump 1.5 meters on Earth, you can jump 9 meters on the moon.

    The moon is very quiet. There is no sound there. There are a lot of grey rocks on it. The moon's sky is always black.

    Our moon is about 384,400 kilometers away from Earth. The total length of the Great Wall is about 21,200 kilometers. We would have to put about ____ Great Walls end to end to reach the moon!

    A new camera made by a company named Netatmo has facial recognition software(面部识别软件). It can tell parents at work that their children have returned from school, or that a package has been taken to their home. It can also tell them if a stranger has entered their home.

    Janina Mattausch is the product marketing manager for Netatmo.

    "The common security(安全)camera at present are not that smart. They can tell if something is moving but they don't necessarily know if it's a human being or, ah, if it's your kids. They don't know the difference, so they will warn you all the time."

    When family members enter a home, the new camera "recognizes(识别)" them and sends information to the owner's smartphone. The owner can choose to see the video then or later. But if an unknown person enters a home, the camera will send the warning that will cause an alarm to sound on the owner's smartphone.

    That is what happened recently to an owner of the smart camera named Damien, He lives in Paris.

    "On a Friday I was at work, attending(出席) a big monthly meeting when my phone warned. At first I told myself, 'Oh, it must be a mistake, maybe I have to set the system again.' But the notice on my phone was telling me that there was a movement in my flat and also a face that the software did not recognize."

    He watched the video and was very surprised by what he saw. "I was watching it live on video. So I felt totally unbelievable and frozen. I asked a workmate to take me back home as fast as possible and I called the police on the way."

    With the help of the video, the police found the intruder(闯A者) later that day.