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    Do you have brown hair? Are you taller than other kids your age? These characteristics were decided before you were born. You got your traits from your parents. They passed their traits on to you through genes (基因).

    Genes carry codes (代码) for blue eyes or brown eyes. Genes say how tall you will get and what color hair you will have. You got half of your genes from your mother. You got half of your genes from your father. So you have your own set of genes. Each person gets different genes for each body part. That is why you look like but not exactly like your brother or sister.

    A dominant (显性的)  gene shows up most of the time. Brown eyes are dominant over bluc eyes. A recessive (降性的)  gene shows up less often. Light hair comes from a recessive gene. Dark hair is more common. Look at the eye color and hair color of the people around you. You will see that this is true.

    Genes help to make you who you are. But they don't tell the whole story. Your genes may help you to be fast and strong. But you still need to learn how to run or swim or skate well.

    Wind power is a very clean source of energy. This is how wind power works. Wind makes windmills spin (旋转). When the windmills spin, they make electricity. Then we can use the electricity.

    A lot of people think that wind power is new, but that's not true.

    For thousands of years, people have used wind to sail boats and move water. We still do those things today, but these days we mostly use wind power to make electricity.windmills

    Wind power is a very popular source of energy. Most people think that we should use it more and more. First of all, it's clean. Windmills don't pollute the environment at all. Second, we can use wind power forever. After all, we will always have wind. Also, wind power is cheap, and it's getting even cheaper.

    A lot of people don't understand wind power very well. They believe that there are problems with wind power, but many of those problems are not real. For example, some people say that windmills are dangerous for birds. They used to be true, but it isn't true anymore. Old windmills killed birds because they spun very fast. New windmills spin slowly, and they aren't dangerous for birds.

    However, there are real problems with windmills. One problem is that many people think windmills are very ugly. This is a problem for people, because windmills are often in very pretty areas. Also, wind doesn't blow all the time, so we can't use wind power all the time. Finally, windmills are noisy.

    Wind power is becoming more and more common. Right now, more than 80 countries use wind power. About 2.5 percent of the world's power comes from the wind. For some countries, that number is a lot higher. Wind power gives Denmark more than 25 percent of its electricity.

    Some people wonder why countries spend millions of dollars on space projects. They want to know how space research helps people on Earth. Actually, space technology helps people on Earth every day. This is called "spinoff technology". Spinoff technology is space technology that is now used on Earth.

    In early space programs, such as the Apollo missions(任务) of the 1960s and 1970s, and in the space shuttle missions today, scientists developed objects for the astronauts to use on the moon and in space. We now use some of these objects every day. For example, we have Quartz clocks and watches with an accuracy of one minute a year. We purify the water we drink with a water filter(过滤器) designed for the astronauts' use in space. The cordless, hand-held tools we use in our homes, such as cleaners, flashlights, drills, and irons came from the technology of these early space programs.

    On cold winter days, we can stay warm with battery - operated shoes and socks, and insulated(绝缘的) coats and jackets. All of these clothes are similar to the spacesuit designs that keep astronauts comfortable in the temperatures of the moon, and are spinoffs from space technology.

    These products are only a few examples of the many ways space technology helps us in our everyday life. No one knows how new spinoff technology from the International Space Station will help us in the future.