Today, nearly five hundred weather stations in sixty countries receive satellite pictures.  When they receive new pictures, the meteorologists compare（比较）them with earlier ones.  Perhaps they may find that the clouds have changed during the last few hours.  This may mean that the weather on the ground may soon change, too.  In their next weather forecast, the meteorologists can say this.
　 So the weather satellites are a great help to the meteorologists.  Before satellites were invented, the scientists could forecast the weather for about 24 or 48 hours.  Now they can make good forecasts for three or five days.  Soon, perhaps, they may be able to forecast the weather for a week or more ahead（提前）.

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    Almost every Chinese person can recite(背诵) the two lines of the famous poem, "Every grain on the plate comes from hard work". But sadly, many of us don't actually get the real meaning of these lines: Don't waste food.

    A CCTV program reported that the food Chinese people throw away every year is enough to feed 200 million people for a year. Do we have too much food? Absolutely not. According to the UN World Food Program, there were 925 million hungry people around the world in 2013, especially in developing countries. Six million children die of hunger every year.

    Chinese people are well-known for being friendly and generous. Many even feel that they lose face if their guests have eaten all the food on the table. Luckily, a number of people have realized the importance of saving food. What should we do in our daily lives to waste less food?

    ⒈ Don't order too much in a restaurant. Only order as much as you want to eat. If you cannot eat all the food you ordered, take the rest of it home.

    ⒉ Don't leave any food in your bowls while having meals.

    ⒊ Keep an eye on what food you have at home. Don't buy too much, especially for vegetables and fruit.

    Have you ever had trouble sleeping in a new place? Lots of people do. And now researchers from Brown University in Rhode Island think they know why. They found that one-half of the brain "remains more awake" than the other half when people are trying to sleep in a new place.

    The sleep findings were reported in Current Biology by Brown University. In their report, the researchers said many people report that they have a harder time sleeping the first night at a hotel or other places outside their home. They call it "first-night influence". "In Japan they say, 'If you change your bed, you can't sleep,'" said Yuka Sasaki, one of the report's writers. "You don't sleep very well in a new place. We all know about it."

    The researchers measured brain waves (测量脑波) for 35 volunteers over two nights in a laboratory. The two nights were a week apart(间隔).They found during the first night the left half of the brain was more active than the right half. This was during the first deep-sleep period, the researchers said.

    Sasaki said a lot of questions remain.

    Researchers did not keep measuring brain waves all night long. So, they don't know if the left half keeps "watch" all night, or whether it" works in shifts (轮换) with the right half later in the night" .They also do not know why the brain activity, at least during the first period of deep sleep, is always on the left half.

    For some, this research may be calming. It is good to know that our brain is "looking out for us" in a new place. But it may not help with sleep. That brain activity, at least according to this new research, makes it harder to get the sleep people need to wake up well rested in the morning.

    Gardening is popular in many parts of the world. It brings us sweet smelling flowers, fresh fruit and vegetables. But you can get more from your garden.

    Gardening helps to keep healthy. Today's people sit indoors for too long and don't get much exercise. When you garden, you have to move around. It's a good chance for you to exercise your body by watering flowers or doing some digging. Besides, when you are in your garden, you can feel the warm sunshine. This means you are getting Vitamin D. It helps your bodies use calcium (钙), which is necessary to keep your bones (骨骼) strong.

    It gets them off computers, televisions and phones. Gardening can be a great teacher to teach children about nature and healthy eating. It can also help them to understand the meaning of "No pains, no gains."

Gardening is a great way to meet people and build relationships. When you are gardening, you are outdoors. So it is a perfect time to communicate with your neighbors. Most people love to talk about their hobbies, and so do gardeners. They usually enjoy showing people what they are growing. And most enjoy sharing advice and stories about their gardens.