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．

当前我国70%的河流湖泊受到未经处理的工业废水和生活污水的严重污染。据世界卫生组织统计，中国每年有10万人因此而丧生。这说明（　　）

①人为因素是导致水污染的重要原因　②经济的发展就应以牺牲环境为代价的

③环境污染已严重威胁到人类的生存与发展　④我国保护水环境已刻不容缓​

①完善我国的基本经济制度

②大力发展非公有制经济

③坚持按劳分配和按生产要素分配相结合

④健全生产要素按贡献参与分配的制度