阅读理解（C）
    Most people want to be happy, but few know how to find happiness. Money and success alone do not bring lasting happiness. Aristotle, a Greek thinker, said, "Happiness depends upon ourselves." In other words, we make our own happiness. Here are a few suggestions 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 fail to enjoy the present. You should enjoy life's simple pleasures快乐, such as reading a good book, listening to your favorite music, or spending time with close friends. People who have several close friends often live happier and healthier lives.
    Another secret to living a happy life is to be active, and have hobbies where you forget your problems and time. Many people experience this dancing, or playing a sport, such as swimming. You can forget about your problems, and only think about the activity. Finally, many people find happiness in helping others. Studies show that people feel good when they spend their time helping others. If you want to feel happier, do good things for someone. You can help a friend with his or her studies, go shopping to buy food for an elderly person, or simply help out around the house by washing the dishes.

已知一个圆的参数方程为$\left\{\begin{array}{c}x=3\cos \theta \\ y=3\sin \theta \end{array}\right.$  ( $\theta$ 为参数)，那么圆的摆线方程中与参数$\phi =\frac{\pi }{2}$  对应的点A与点$B\left(\frac{3}{2}\pi ,2\right)$  之间的距离为____

巴中某超市卖的纯碱（Na₂CO₃）产品往往含有少量的氯化钠（NaCl），化学兴趣小组的同学通过实验来测定该纯碱样品中纯碱的质量分数．他们取12g纯碱样品放入烧杯中，逐滴加入稀盐酸至不再产生气泡为止，共消耗盐酸100g，烧杯中没有残留不溶物，称得反应后溶液的质量为107.6g．计算：

2013年9月16日，巨星云集的2013世界斯诺克上海大师赛正式开杆，丁俊晖率领总共12名中国职业球手亮相，丁俊晖再次获取排名赛冠军，如图所示是丁俊晖比赛的照片，台球在没有被打出时，台球受到的重力和支持力是一对____ （选填“平衡力”或“相互作用力”）．

不是每一朵花都能结出果实，能结出果实的花一定（    ）

①长有雌蕊和雄蕊 ②长有雌蕊  ③经历了自花传粉  ④经历了传粉  ⑤经历了受精