题干

下列能说明生物能对外界刺激出反应的是(  )

A:动物以植物为食

B:含差羞草的叶片受到触动会合拢

C:鲸呼气时会产生雾状水雾

D:西瓜能进行光合作用制造有机物

上一题 下一题 0.0难度 选择题 更新时间:2016-06-01 03:04:01

答案(点此获取答案解析)

B

同类题4

    Happiness is important for everyone. Most people want to be happy but few know how to find happiness. Money and success don't bring lasting happiness. Happiness depends on ourselves. In other words, we make our own happiness.
    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!