A plant is a living thing. It uses its many parts to grow from a small seed to a large plant. Each part helps the plant stay healthy. Plants also need sunlight to grow. They get light from the sun and minerals from the soil. These things help the plant stay alive and grow. 

      A seabird named Lydia recently made a 26-day nonstop(不间断的)journey of about 2,500 mi­les, just to search for food for her baby. She is fitted with a satellite tracking device (卫星跟踪仪). Her trip started on Oct. 18 from Christmas Island in the Indian Ocean. The trip is known as the lon­gest nonstop journey by one of these endangered seabirds.

      Before that, this kind of birds was known only to fly a few hundred miles from where they live, staying away for just a few days at a time. They usually fly over the sea.

      The scientists feel it strange that Lydia made such a long, nonstop journey and flew overland. So the above facts raise some serious questions about efforts to stop the decline(减少)of the birds. The number of the birds has fallen by 10 percent over the past 20 years.

Besides, the scientists are surprised that she was away from her baby for such a long time. They wonder why she needed to go that far. Maybe it shows that fish resources (资源)around Christmas Island are not large enough now. That might explain the slow decline of the bird 一 sea pollution(污染) is serious.

    Imagine a perfect day: the weather is good and everything seems fine. When, suddenly, your mobile phone loses its signal, the television has no programs, and you can't get online with your computer.

    What has happened? These are just the types of problems a solar storm（太阳风暴）might cause. You may not think of storms as putting our society in danger. But today, a solar storm is as serious as other bad events, such as earthquakes.

    A solar storm is caused by solar flares（太阳耀斑）: large explosions（爆炸）near the sun that can give off lots of energy. The strong energy can stop the satellite systems（卫星系统）that control our computers, telecom networks and so on. These storms can even cause the power to go out for weeks or months.

    In the past few months, scientists have recorded some of the strongest sun flares in years. The most recent one happened around Valentine's Day, 2011. It caused radio and satellite signals to go down in some northern cities in China.

    “Solar flare activity is going to be much worse than what we've seen in the past. We're not talking about a few cities losing power, it could be half of the country, maybe more.” SolarStormWarning.com, a US website about space weather, warned.

    Scientists say that little can be done to predict such a storm. Governments around the world are trying to work together before the next storm, although they are not sure when that may happen.

    Animals grow up（成长） in different ways. Some newborn（初生的） animals are helpless but their mothers protect them. A newborn kangaroo is very small. It is only a few centimeters（cm）long. It closes its eyes and doesn't have hair. It stays safe in its mother's pouch（育儿袋）for a long time.

    A newborn monkey can not walk. Its mother carries it everywhere.

    Other baby animals can walk soon after they're born. They learn to run with their mothers when danger is near. A baby zebra can run, an hour after it is born.

    Some baby animals are born in a place that is safe. Baby wolves are usually born in big holes with little light. Other baby animals are born in the open. A baby elephant is often born on open land.

    Many people know Shanghai's beautiful night view(景色), especially the colorful lights from the buildings. Light helps us see and makes the environment more beautiful. However, too much light becomes a kind of pollution but many of us pay little attention to this pollution or even ignore it. In fact, it causes a lot of problems. Light pollution can be almost as bad as carbon dioxide pollution.

    Too much light can do harm to our health. First, it can make us feel bad and we can't sleep well. Second, lights need electricity, and creating electricity will give off greenhouse gases. This affects the air and causes breathing problems. Third, study shows people living under bright light for long can have cancer more easily.

    Too much light may be even harmful to wild animals. Thousands of birds die from it each year. Some hit into the light buildings, because they can't see clearly in the strong light. Some birds sometimes lose their ways in the bright light Sea turtles(海龟) can't find the dark beaches to lay their eggs.

    To protect humans and wildlife, we should take measures to reduce the use of lights at night.