题干

 综合作图﹣﹣小雨房间的灯:

小雨的房间里有两盏灯.开关S1控制吊灯L1和L2;开关S2控制壁灯L3;开关S3和S4控制床头灯L4,使它有两种不同的亮度.

现在有一个电源、4个开关、4个灯泡、一个定值电阻和若干导线,请你设计上述电路,将电路图画在方框内.

上一题 下一题 0.0难度 选择题 更新时间:2014-07-02 11:02:49

答案(点此获取答案解析)

解:

由题,开关S1控制吊灯L1和L2,说明S1在这两灯的干路上;

开关S2控制壁灯L3,说明S2在灯L3支路上;

开关S3和S4控制L4,使它有两种不同的亮度,通过开关转换,可将定值电阻与L4串联或L<

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    Some people believe that if they are wealthy, they will be able to do anything they want, which means happiness. On the other hand, some people believe that holding a high position in the government is happiness. In this way, you have not only money, but also many other things which can't be bought by money. However, other people believe that having lots of money is not happiness, nor is holding a high position in the government. These people value(重视) their beliefs, or their intelligence, or their health. They think these can make them happy.
    Here are a few ways to help you be happier.
    The first secret of happiness is to enjoy the simple things in life. Too often, we spend so much time thinking about the future, for example, getting into college or getting a good job, that we don't enjoy the present. You should enjoy life's simple pleasures, such as reading a good book, listening to your favorite music, or spending time with close friends. People who have close friends usually enjoy happier and healthier lives.
    The second secret of happiness is to be active. Many people go dancing or play sports. People can forget about their problems and only think about the activities.
    Finally, many people find happiness in helping others. According to studies, people feel good when they volunteer their time to do many meaningful things for other people. If you want to feel happier, do something nice for someone. You can help a friend with his or her studies, go shopping to get food for an old neighbor, or simply help around the house.
    Now maybe you know how to find happiness!