题目

用所给单词的适当形式填空。 Victor used to be such a good runner that he 1        (win)nine awards by the age of 18．Then one day while he  2        (run)along the roadside，an accident suddenly happened to him.．Unfortunately both of his legs 3        (injure)seriously by a car out of control．Since then，he  4       (not be)able to walk any more． After a long time，however，he knew life 5        (not stop)for him．He focused on what he could do instead of what he lost．He realized that there were many possibilities for the disabled如图，杠杆处于平衡状态．请在图中画出小球所受重力的示意图和作用在B点最小力的方向及力臂．