题目

While happiness does not happen by chance, you don’t need to change our entire life to find it. Start your journey to a happier you by developing these easy habits. Work Out Often Staying active can make you feel more enthusiasm for daily activities. So hit the gym or take up a sport that suits you best. Working out does you more good than burning off calories and strengthening your muscles.   36   That’s why healthy people are generally 20% happier than unhealthy people. Volunteer   37   Using your skills to assist the less fortunate can boost your happiness. After all, it i蜡烛燃烧之所以是化学变化，是由于蜡烛在燃烧时（    ）    A．先熔化      B．再发出黄光    C．放出大量的热     D．生成了水和二氧化碳