题目

Now, the VOA Learning English program (节目) Words and Their Stories. Today, we talk about something that everyone has around the world.It is free. You can do it anywhere. And it makes you feel good! Right! It's laughter. Laughter can spread easily among people. For example, when we hear someone laughing in a room or on a train, we start laughing too - even if we have no idea why.____ 58 In fact, many doctors say if you laugh more often, you will feel happier and live longer. But when you are ill, if you do not take medicine (药), it is wrong. If one laughs a lot, he or she must be a happy19、城区某绿化带2006末年已有树木1000棵，计划到2009年末将达到4500棵．该绿化带2007年植树500棵，如果该绿化带2008年和2009年植树棵树的年增长率相同，那么2009年应植树多少棵？