How many people will go for the picnic tomorrow?

    Everybody can suffer from stress．No matter what your age is，you can feel stressed out by things that are happening in your life．Teenagers，however，have many more opportunities to get stressed than people in any other age group．Being a teenager is hard．You are not a child any more，but you are not an adult，even though you have to deal with some very grown-up problems and decisions．Families can be one of the biggest causes of stress，such as problems with parents arguing at home．or problems with brothers and sisters．Teenagers also have a lot of stress from school，either from their teachers or from their friends．Some teenagers also feel stressed about choosing their education after high school．Getting a place at university can be very difficult and some cannot afford to go to university．The stress about getting a job when finishing school is hard for some teenagers．There are so many young people finishing school and not enough jobs for them．Sadly，there is nothing we can do to remove these causes of stress from the 1ives of teenagers，but you can learn the best way to deal with it．Talking to people is one of the best ways to deal with stress．It may sound simple，but it is true．A problem shared is a problem halved．

猜想1：加水可以起到稀释的作用，使反应速度变缓．  猜想2：…

并根据猜想进行了实验：每次取15毫升15%的过氧化氢溶液，稀释成不同溶质质量分数，在其他条件相同的情况下进行实验．记录数据如下：