使分式$\frac{x^2-1}{x+1}$的值为0，这时x=____ 

____     r_ _er

____    pen_i_ c_ _e

____     c_a_on

____     s_h_ol_a_

____    r_b_er

一女孩在乘车回家的路上，遇见几个行为不轨的青年对她挑衅，她假装向售票员问路伺机摆脱他们的纠缠，她的行为（     ） 

我国运动员刘翔，多次在世界大赛上打破110m栏的世界记录，他的跨栏可以说是跑得非常快．我们在看电视转播时，虽然他总没有离开小小的电视屏幕，但总能感觉他如同飞人，这是因为我们所选取的参照物是（　　）

    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．