一根长60厘米的弹簧，一端固定．如果另一端挂上物体，那么在正常情况下物体的质量每增加1千克可使弹簧增长1.5厘米．

观察下列图形：已知a∥b，在第一个图中，可得∠1+∠2=180°，则按照以上规律，∠1+∠2+∠P₁+…+∠P_n={#blank#}1{#/blank#}度．

B

    In your life, there are a lot of people around you. They are your relatives, neighbors, friends or classmates. Sometimes you get along well with them, but sometimes don't. What can you do when someone hurts you? Most people may be angry or even fight with him. But it's not a good idea. You'd better forget all this and forgive (宽恕) him.

    Maybe it's not easy for you to do that, but it's possible. Please remember: Keep a good mood, and you will keep healthy. Staying angry with others, in fact, means letting others' mistakes treat yourself unfairly.

    How can you forgive others?

    First, think of something pleasant and try to get yourself happy.

    Second, don't wait others to say sorry to you. If anyone hurts you, he won't say sorry to you. He may just want to hurt you or just don't see things the same way.

    Third, try to see things in others' shoes. You can understand their minds better and make yourself a little happier.

    At last, try to know yourself very well. Whose mistakes caused that, yours or others'? If it's your fault (错误), try to say sorry to them. If it isn't, smile at the thing.

B

    In your life, there are a lot of people around you. They are your relatives, neighbors, friends or classmates. Sometimes you get along well with them, but sometimes don't. What can you do when someone hurts you? Most people may be angry or even fight with him. But it's not a good idea. You'd better forget all this and forgive (宽恕) him.

    Maybe it's not easy for you to do that, but it's possible. Please remember: Keep a good mood, and you will keep healthy. Staying angry with others, in fact, means letting others' mistakes treat yourself unfairly.

    How can you forgive others?

    First, think of something pleasant and try to get yourself happy.

    Second, don't wait others to say sorry to you. If anyone hurts you, he won't say sorry to you. He may just want to hurt you or just don't see things the same way.

    Third, try to see things in others' shoes. You can understand their minds better and make yourself a little happier.

    At last, try to know yourself very well. Whose mistakes caused that, yours or others'? If it's your fault (错误), try to say sorry to them. If it isn't, smile at the thing.

今年5月我12日我国四川省汶川县发生特大地震。全国人民万众一心，众志成城。图(1)是我市某中学“献爱心，抗震救灾”自愿捐款活动学生捐款情况制成的条形统计图，图(2)是该中学学生人数比例分布(已知该校共有学生1450人).

阅读下面甲、乙两文，完成问题。

【甲】

       北山愚公者，年且九十，面山而居。惩山北之塞，出入之迂也，聚室而谋曰：“吾与汝毕力平险，指通豫南，达于汉阴，可乎？”杂然相许。其妻献疑曰：“以君之力，曾不能损魁父之丘，如太行、王屋何？且焉置土石？”杂曰：“投诸渤海之尾，隐土之北。”遂率子孙荷担者三夫，叩石垦壤，箕畚运于渤海之尾。邻人京城氏之孀妻有遗男，始龀，跳往助之。寒暑易节，始一反焉。

       河曲智叟笑而止之曰：“甚矣，汝之不惠！以残年余力，曾不能毁山之一毛，其如土石何？”北山愚公长息曰：“汝心之固，固不可彻，曾不若孀妻弱子。虽我之死，有子存焉；子又生孙，孙又生子；子又有子，子又有孙；子子孙孙无穷匮也，而山不加增，何苦而不平？”河曲智叟亡以应。

【乙】

       鲁公治^①园，欲凿池，父曰：“无地置土。”公遂止。或曰：“土可垒山。”公善之，欲行。妻曰：“不畏小儿女颠踬^②耶？”公复止。或曰：“筑径通之，设栏护之，又何忧焉？”公从之，又欲行。家人有止之者曰：“园成必添仆妇，下房不足，甚可虑也。”公犹夷^③不能决，事又寝^④。

      【注】①治：修建。②颠踬：被东西绊倒。③犹夷：迟疑不决的样子。④寝：停止。

阅读下面甲、乙两文，完成问题。

【甲】

       北山愚公者，年且九十，面山而居。惩山北之塞，出入之迂也，聚室而谋曰：“吾与汝毕力平险，指通豫南，达于汉阴，可乎？”杂然相许。其妻献疑曰：“以君之力，曾不能损魁父之丘，如太行、王屋何？且焉置土石？”杂曰：“投诸渤海之尾，隐土之北。”遂率子孙荷担者三夫，叩石垦壤，箕畚运于渤海之尾。邻人京城氏之孀妻有遗男，始龀，跳往助之。寒暑易节，始一反焉。

       河曲智叟笑而止之曰：“甚矣，汝之不惠！以残年余力，曾不能毁山之一毛，其如土石何？”北山愚公长息曰：“汝心之固，固不可彻，曾不若孀妻弱子。虽我之死，有子存焉；子又生孙，孙又生子；子又有子，子又有孙；子子孙孙无穷匮也，而山不加增，何苦而不平？”河曲智叟亡以应。

【乙】

       鲁公治^①园，欲凿池，父曰：“无地置土。”公遂止。或曰：“土可垒山。”公善之，欲行。妻曰：“不畏小儿女颠踬^②耶？”公复止。或曰：“筑径通之，设栏护之，又何忧焉？”公从之，又欲行。家人有止之者曰：“园成必添仆妇，下房不足，甚可虑也。”公犹夷^③不能决，事又寝^④。

      【注】①治：修建。②颠踬：被东西绊倒。③犹夷：迟疑不决的样子。④寝：停止。

从标号分别为1，2，3，4，5的5张卡片中，随机抽取一张，下列事件中，必然事件是（    ）

从标号分别为1，2，3，4，5的5张卡片中，随机抽取一张，下列事件中，必然事件是（    ）

乘法公式的探究及应用.

如图，△ABC中AB=AC，AB的垂直平分线MN交AC于点D．若AC+BC=10cm，则△DBC的周长为{#blank#}1{#/blank#}

已知：如图AB∥CD，EF交AB于G，交CD于F，FH平分∠EFD，交AB于H，∠AGE=50°，求∠BHF的度数．

阅读下面材料，按要求作文。

       星星羡慕太阳的耀眼，太阳欣赏星星的柔和。是的，星光和阳光都能引动诗情。对此，你有何经历、见闻，或有何看法、感悟，请自拟标题写一篇记叙文或议论文。

       要求：不少于600字；不得出现真实人名、校名、地名。

如图，已知，BD与CE相交于点O，AD=AE，∠B=∠C，请解答下列问题：

如图，已知，BD与CE相交于点O，AD=AE，∠B=∠C，请解答下列问题：

如图，已知，BD与CE相交于点O，AD=AE，∠B=∠C，请解答下列问题：

如图，已知，BD与CE相交于点O，AD=AE，∠B=∠C，请解答下列问题：

阅读下面一段文字，按要求回答问题。

       ①九宝澜黄金沙滩位于湄洲岛西南突出部，状如一钩新月，悬挂在zhàn lán的大海上。②它面对浩瀚无垠的碧海，背依千亩葱笼的防护林，滩头奇峰挺秀，怪石嶙峋。③大自然的鬼斧神工，令人（赞叹所看到的事物好到了极点）。

阅读下面一段文字，按要求回答问题。

       ①九宝澜黄金沙滩位于湄洲岛西南突出部，状如一钩新月，悬挂在zhàn lán的大海上。②它面对浩瀚无垠的碧海，背依千亩葱笼的防护林，滩头奇峰挺秀，怪石嶙峋。③大自然的鬼斧神工，令人（赞叹所看到的事物好到了极点）。