课前两分钟发言 可以说什么事例?发生在身边的

后面每分钟的长度都比前一分钟的长度减少相同的米数
500-420=80就是后两分钟比前两分钟少跑得,是后面每分钟比前一分钟的长度减少米数的4倍
后面每分钟比前一分钟少跑80÷4=20米
第一分钟跑500÷2+20÷2=260,第二分钟跑240米

今天,我怀着愧疚和懊悔给您写下这份检讨书,以向您表示我对未放学离开座位这种不良行为的深刻认识.
这是一次十分深刻的检查,我对于我这次犯的错误感到很惭愧,我真的不应该在还没有放学就离开座位,我不应该违背老师的规定,我们作为学生就应该完全的听从老师的话,而我这次没有很好的重视到老师讲的话.我感到很抱歉,我希望老师可以原谅我的错误,我这次的悔过真的很深刻.
不过,人总是会犯错误的,当然我知道也不能以此作为借口,我们还是要尽量的避免这样的错误发生,希望老师可以相信我的悔过之心.“人有失手,马有失蹄”.我的不良行为不是向老师的纪律进行挑战.绝对是失误,老师说的话很正确,就是想要犯错误也不应该再您的面前犯错误,我感到真的是很惭愧.
相信老师看到我的这个态度也可以知道我对这次的事件有很深刻的悔过态度,我这样如此的重视这次的事件,希望老师可以原谅我的错误,我可以向老师保证今后一定不会在早自习及其他任何课上说闲话的.
望老师给我一个改过自新的机会.老师是希望我们成为社会的栋梁,所以在今后的学习生活中我会更加努力,不仅要把老师教给我们的东西学好,而且更要学会如何做人,做一个对社会有用的人,一个正直的人.
以上只是个人观点,

有一则故事是这样的：一位魔术师在苏丹面前表演魔术,他的精彩表演使苏丹大为赞赏,被称为“天才”.
可一位大臣说：“陛下,大师不是天上掉下来的,这位大师的技艺,是他勤奋练习的结果.”大臣的反驳让苏丹大为生气,便让大臣到城堡里反思,并送他一只小牛犊做伴.
这位大臣在城堡里每天练习抱小牛犊,从下面一个台阶一直走到塔顶.几个月后,小牛犊长成了一头很结实的公牛,大臣的力量也大增.
一天,苏丹想看看大臣,当他看到大臣抱着这头大公牛时,非常惊讶,“真主啊!这多么神奇,不可思议啊!”这个大臣说：“陛下,大师不是天上掉下来的,我的力量是我勤奋练习的结果.”
不同的心态,会造成不同的结果,只有流勤劳的汗,吃勤劳的饭,吃起来才香甜.在距成功的路上,只要我们多走几步,既可与成功签约.
总之,没有勤奋就没有成功,没有付出就不可能有收获；有了汗水才有成绩,有了永恒的信念就一定能实现目标.

可以说做的游戏,同学间有趣的对话或者恶作剧,看故事心得体会……还有对下一节课激动心情,因为喜欢那老师的课,做了什么准备有什么联想类

There was a man who had seven sons,but he had no daughter,greatly though he longed for one.At last his wife told him that they could again expect a child and,sure enough,when it was born it was a baby girl.There was great rejoicing,but the child was weak and puny,so weak that it had to be christened at once.The father told one of the boys to go quickly to the spring and fetch christening water; the other six ran along with him,and because each of them wanted to be the first to dip the jug into the well,it fell in and sank.So there they stood and didn‘t know what to do,and none of them dared go home.When they didn‘t come back their father got impatient and said:“ I‘ll wager they‘ve been playing some game again and forgotten all about it,the godless brats.“ He was afraid the little girl would have to die unbaptized,and in his rage he cried out:“ I wish those boys would all turn into ravens.“ He‘d scarcely spoken the words when he heard a whirring of wings in the air overhead,looked up and saw seven coal-black ravens flying away.
有个人,他有七个儿子,他很希望有个女儿,可是怎么盼也没有.好不容易,妻子又怀孕了.生下来一看,果然是个女孩.他们非常高兴.但是孩子太小,又非常虚弱,非得马上急救洗礼不可.父亲打发一个男孩立即到井台去打洗礼水,其余六个也跟着去了.在井台旁,他们都争着先打水,结果罐子掉进井里,沉了下去.他们不知道该怎么办才好,都真楞楞地站在那儿,谁也不敢回家了.父亲在家里等得不耐烦了,就说：“我敢说这些无法无天的孩子一定是贪玩,把打水的事给忘了.”他担心女孩子不经洗礼会死,就生气地大声喊起来：“淘气鬼,都变成乌鸦才好呢!”这话刚出口,就听到头顶有“吧哒吧哒”鸟儿拍打翅膀的声音.他抬头一看,只见空中有七只漆黑漆黑的乌鸦飞过去了.
The parents were unable now to take back the curse,and yet,grief-stricken as they were at the loss of their seven sons,they look some comfort from their beloved little daughter,who soon got well and strong and became more beautiful with every day that passed.For a long time the little girl didn‘t even know that she had had brothers,for her parents took care not to mention them,but one day by chance she heard some peop

180 除 2 90
90乘 15 等于 1350
1350大于980
能

这就是复杂了- -
扯到了物理的加速速运动,减速度运动,匀速运动和变速运动
但如果说简单的,不就是前2分钟走的距离加起来除2吗?
照这么说,就是前2分500/2=250M/分,后是450/2=225M/分
还是说,我智商低了-

250,300,300

拿一个本子站在讲台上,谁说话就记名,罚抄语文书最长的课文3遍,如果你们班值日的话,再罚扫地一个星期,一星期以内如果还有一点灰尘,就罚扫地一个月,接着一学期,然后一年.就是这样!最有效!不过要和老师讲讲这个意见.

答：设小华刚超过小明时时间为x小时,
15x+20=45x
x=23小时
超过前2分钟两人相距：15*（23-130)+20-45*（23-130)=1km
希望对你有所帮助