题目

有理数a，b，c在数轴上的位置如图所示，化简|a+b|-|b+c|-|c+a|是( ) A . 2a B . 2a+2b C . -2b D . a-b 答案：C When you make a mistake，big or small，cherish（珍惜）it like it is the most valuable thing in the world． Most of us feel bad when we make mistakes．That is only natural：most of us have been taught from a young age that mistakes are bad，and that we should try to avoid（避免）mistakes．We've been blamed when we make mistakes at home，school and work． Yet without mistakes，we could not learn or grow． If you think about it that way，mistakes should be cherished anti celebrated for being one of the most amazing things in the world：they make learning possible，and they make growth and improvement possible． Think about how you learn：you don't just read about painting，or writing，or computer programming．．．and know how to do them right away． Instead，you get information about something，from reading or from another person or from watching carefully．．．then you have a model in your mind．．．then you try it in the real world．．．then you make mistakes．．．then you revise（修改）the model．．．and repeat，making mistakes，learning from those mistakes，until you have learned how to do something． Mistakes ate how we learn to do something new--because if you succeed in something，it is probably something you already knew how to do．You haven't really grown much from that success--at most it is the last step on your journey，not the whole journey．Most of the journey was made up of mistakes，if it is a good journey． So if you value learning，if you value growing and improving，then you should value mistakes． Cherish your mistakes．Smile． 1．According to the passage，people usually think that _________． A．it is bad to make mistakes                         B．it is natural to make mistakes C．it is easy to avoid mistakes                          D．it is hard to correct mistakes 2．The passage tells us that people could not learn or grow without _________． A．making plans                                           B．doing research C．making mistakes                                        D．doing experiments 3．The proper title for the passage is _________． A．Why YOH Should Realize Your Mistakes B．Why You Should Correct Your Mistakes C．Why Yon Should Avoid Making Mistakes D．Why YOH Should Cherish Your Mistakes