如图1所示，木板OA可绕轴O在竖直平面内转动，某研究小组利用此装置探索物块加速度a与斜面倾角θ之间的关系．已知物块始终受到方向沿斜面向上、大小为F=8N的力作用，由静止开始运动，物块的质量m=1kg，通过多次改变斜面倾角θ，重复实验，用测得的数据描绘了如图2所示的a﹣θ关系图线．若物块与木板间的动摩擦因数为0.2，物块与木板间的最大静摩擦力等于滑动摩擦力，g取10m/s²．试问：

小明在抄分解因式的题目时，不小心漏抄了x的指数，他只知道该数为不大于10的正整数，并且能利用平方差公式分解因式，他抄在作业本上的式子是x^□﹣4y²（“□”表示漏抄的指数），则这个指数可能的结果共有（　　）

古诗文填空。
①黑云压城城欲摧，                       。（《雁门太守行》）
②                             ，病树前头万木春。（《酬乐天扬州初逢席上见赠》）
③关关雎鸠，                        。（《关雎》）
④                                  ，自缘身在最高层。（《登飞来峰》）
⑤                              ，                                 ，游人去而禽鸟乐也。（《醉翁亭记》）
⑥杜甫在《春望》一诗中，描写国都沦陷但山河依旧；春天降临却乱草丛生的诗句是：                          ，                             。
⑦同学们即将告别母校，离别之时，请选用古诗文中的“                                ，                                    ”的句子来表达惜别之情。

    Do you like reading stories? Maybe you will answer, “No, I am not a child any more!” Yes, children all over the world always love stories.

    Chinese children are 1in Monkey King's story. It 2a popular bedtime story in China for many years. In fact, adults also love the story a lot. For them, Monkey King has become a very 3part in the memory of their childhood. The clever and humorous monkey 4the hearts of many Chinese people. British boys and girls all know Alice's Adventuresin Wonderland well. As the name 5, it's a story full of dangerous but exciting trips. Children laugh, cry and even get frightened with Alice together while reading the story. Most American kids have read The Adventures of Tom Sawyer, by the famous writer Mark Twain. Everyone likes the brave boy who also has lots of 6. Some scenes of the story may make your heart go faster, for Tom and his friends meet some very bad men and are usually 7. Of course in the end, they beat the bad ones.

    You may also ask me 8I like stories. Yes, I have liked them since I was very young. At that time, I often 9all my pocket money on story books. For me, stories are much more 10than chocolate! They help me learn a lot. So either young or old, let's enjoy stories.