一分钟内回答追加50分,两分钟内45……一元二次方程的解法~有米有会的来(⊙o⊙)!

第一分钟内没有通过车的概率由泊松分布性质可知,是p(0;1.8).查表可知：0.165299.
不正确.因为80数字较大,翻表可以知道,一般该数字应在5以内,较小.数字较大则分布拨动较大,不宜用泊松分布表示.

有两种方式能回到巢穴,①作直线运动：向巢穴的反方向爬行,2分钟；②作圆周运动：在2米为直径的圆上爬行也能回到巢穴,4分钟.

是并排在起跑线。。。？

6*3.14=18.84（平方厘米）
刚考完,考试题目吧,六年级的!

10分之7,8分之5,6分之3,5分之2,9分之6,

The company in line with "quality and considerate service, conscience wins, common development" and put California beef noodle king this one brand is making the whole service type, rapid global brand fast food in. The company in developing and set up a good brand image in the original brand, added some innovative dishes, let before varieties of single type of California beef noodle dishes, drab and scattering... More let members get new development, new success, our company sincerely unite to California beef noodle parties members, love to seize the opportunities and hand in hand together create franchising fast-food business.

解题思路：汽车做初速度为0的匀加速直线运动，根据运动规律，位移与运动时间的平方成正比求解即可．

汽车做初速度为0的匀加速直线运动，根据位移时间关系x=
1
2at2有：

x1
x2=

t21

t22
即汽车前10s内的位移x2=

t22

t21x1=
102
602×540m=15m
故选A．

点评：
本题考点： 匀变速直线运动的位移与时间的关系．

考点点评： 掌握初速度为0的匀加速直线运动的位移时间关系是解决本题的关键．

1.)40I²+60I²=9W I=0.3A U=0.3A(40+60)=30V
2.)P1=I²R1=0.09*40=3.6W
3.)Q=I²R2T=0.09*60*60S=32.4J

25

背课文得老老实实的背,一篇很长的作文,也要花很长的时间背.如果一分钟内,我相信背不好

网上找的 不是很长 自己在改改吧 beautiful world 环保英语演讲稿　　Hello:　　everyone!Now I want to talk about a beatiful world!　　When I was young,I always dreamed that I lived in a beautiful country.There were many flowers and trees around our city.We counld hear the birds singing and see the children dancing.The streets were clear and the the air was very fresh!How nice it was!But that only was a dream of mine!How I wish that it would be come true!So I think we should do something to protect our environment.Everyone should make a contribution to protect the environment.　　Taking care of our environment is very important.Wherever you live,you can do something around your neighbourhood.　　Have you ever thrown any litter onto the ground?Have you ever drawn pictures on public walls?Have you ever spat in a public place?Have you ever cut down trees?If your answers are "No",it means that you have already helped protect our environment.　　It is our duty to keep our envionment clean and tidy.You might ask yourself,"Have I ever picked up some rubbish and thrown it into a dustbin?Have I ever collected waste paper or bottles for recycling?Have I ever planted any trees or flowers in or near my neighbourhood?"If your answers are"Yes",it means that you have already done something useful to improve the environment.　　Now I want to say :Let`s do our best to make our world more beautiful!

It's my great honor to be invited here to give a speech.As a student I think We should seize every opportunity to conquer English and make lifelong friends with people throughout the world.By conquering English,we can help ourselves and others.
We are human beings,not animals.We know what we want to do.We know our destiny is in our hands.With hard work and determination,we can do anything we set our minds to do.
As long as you open your heart.
As long as you are devoted.
As long as you are crazy.
As long as you forget about your face.
As long as you open your mouth wildly.
As long as you broaden your mind.You will conquer English and expand your horizons.You will overcome all the obstacles that hold you back.
We are the future of China,the future of Asia,and the future of the world!
We can make the world a better place.
We can make a difference.
We desire to win.
We must win!
We will win,absolutely,and without any doubt!
we can make it.we strongly believe that you will make it too!
Let’s do it together!
We have confidence !
I had a dream ,when I was a child .The dream is taht I could to be a teather ,because I think the teather can help the people know more and more knowledge ; they can save the people who is in trouble ;they like the Angels !To be a teather must be know a great deal of knowledge ,and must keep kind-hearted ,and sometimes even have a little sense of humor .Maybe it is very hard,but I ' ll try my best to make it come true .We should believe in oursevise !

这个问题……太有问题了.拉力才400N,不借助工具是举不起900N的泥土的.

你理解有一点偏差
是因为这一分钟相对前一分钟是上涨的,才把这一分钟的成交额定义为资金流入,如果这一分钟相对前一分钟是下跌的,这一分钟的成交额就定义为资金流出,资金流入-资金流出才是资金净流入.资金净流入可以是正数,也可以是负数,一般情况下股票或者板块上涨了,资金净流入为正数,不能反过来理解为,资金净流入为正数,股票就会上涨,这是把因果倒置了!
不过也有出现股票下跌了,一天的资金净流入为正数的情况,这种情况比较少.其实这个指标意义不是很大!

解题思路：首先估测出中学生的重力，而跳绳的过程是克服自身重力做功的过程，知道每次跳的高度，可利用公式W=Gh计算出所做的总功，又知道做功的时间，再利用公式P=[W/t]计算出跳绳时的功率．

初中生体重大约为500N，h=6cm=0.06m，则他跳绳的总功：
W=nGh=180×500N×0.08m=7200J，
则他跳绳的功率：
P=[W/t]=[7200J/60s]=120W，
由选项可知C较符合．
故选C．

点评：
本题考点： 功率的计算．

考点点评： 考查功与功率的计算，关键是重力的估测，要注意的是跳绳所做的总功（等于每次所做的功乘以跳绳的次数），在计算过程中要注意单位的换算．

Nuwa was a goddess.One day,she took some mud and made the first person.She liked the person and wanted to make lots of people.She made more with her hands but it was very hard work.
Then she had another idea.She took a branch and put it in the mud.The drops ofmud hit the ground and became people.Soon there were lots of people.They worked hard and live happily.
Then,one day,a terrible storm came.It was very strong.It made a holein the sky and it rained and rained.
There was water everywhere.Nuwa wanted to save the people,so she built a fire and meiled rocks.She took some of these rocks and flews into the sky.She worked for seven days and seven nights.Finally,Nuwa fixed the sky and the people were safe again.(我打了好久呀!累)
这个故事是：Nuwa fix the sky女娲补天
1.How did Nuwa make the first person?
2.How did Nuwa make peoplevery quickly?
3.How did Nuwa fix the hole in the sky?

长和宽的和是：96÷2=48cm
长是：48x7/12=28cm
宽是：48-28=20cm
面积：28x20=560cm²
不懂的欢迎追问~

这不是椭圆的基本画法吗?将2个钉子分别固定在两个点（之间的距离不能大于绳子的长度）,然后将绳子的两端固定在钉子上,将笔固定在绳子上,但能随着绳子的移动在绳子上滑动.随着绳子滑动一周得到的图形就是椭圆了

yes,but it's not mine

【1】W=FS=15m乘以3乘以2000N=90000J
P=W/t=90000J/60S=1500W
【2】这一问是求不出来的,因为不知道里面的货物的质量是多少
如果你知道货物的质量我可以在帮你算
算法都是一样的：
W=FS【拉力做的功就是总功】,W=Gh【物体做的功就是有用功】
知道这两个后在用：【效率=W有/W总】这个公式就可以算出来了

a+100X1=a+100米
这个同学一分钟内跑了a+100米

不能不令人哀伤与同情.

一共要花费7.1元

My Chinese name is ***, and my English is ***.I am thirteen years old.I am a happy girl/boy.I like singing and reading. My favourite food is KFC. English and Chinese/Science/Math/History is my favorite subjects.There are three/four people in my family.MY father,mother,brother and I. I love them very much.Today,I am so glad to meet you. I want to make friends with you. Yesterday is a history,tomorrow is a mystery,and today is a gift.So I wish : Everybody good good study, day day up.That's all. tahnk you .我的中文名字是***,我的英文名字是***.我13岁,是个快乐的女孩/男孩.我喜欢唱歌和阅读.KFC是我最喜欢吃的食物.英语和语文/自然/数学/历史是我最喜欢的科目.我家有4个人.我爸爸,妈妈,弟弟和我.我非常爱他们.今天我很高兴认识你们.我想和你们做朋友.昨天已是历史,明天还是个未知,今天是份礼物.所以我希望每个人都好好学习,天天向上.就这样,谢谢!

根据条件列两个方程
180＜2a＜270
14a=360n(n取整)
解出来是n取4,5都可以,所以a就360＊4/14或360＊5/14.

Are you waitting for the bus?

17+3+19 23+7+9

人生自古谁无死?留取丹心照汗青.

A Lesson Learned -------family values
He gathered us and the voice and gesture showed that one of us had done something wrong.
"Which one of you did this?" he asked in a sharp voice.
We all stared down at the floor where there a child's handwriting in chalk.I stood there,and had hoped that no one else could see it.I was scared,the only words that came from my mouth were,"Not me,dad." My sisters denied it as well.Of course,we knew that one of us must have done it.But I just couldn't find the courage to tell the truth.
He continued to stand there for a few moments."Since none of you seemed to have done it,then you all get the punishment." I stood there and said nothing.The last thing I wanted was a slap!
"I did it," my sister said.I looked around to see my sister come forward.Why was she taking the blame for something I did?I stood there knowing my sister was going to get spanked for something I did.
We didn't talk about that day for many years.But,I had already figured out why my sister took the blow for it.She had become my protector,my best friend.And because of that,she would have rather taken the pain herself than see me suffer.
When I think back to that day,I know I learned the value of family,of a sister who would do anything for me.And I'm glad to say that now I would do the same for her.

1)TOM'S EXCUSE
Teacher:Tom,why are you late for school every day?
Tom:Every time I come to the corner,a sign says,"School-Go
Slow".
汤姆的借口
老师：汤姆,您为什么每天上学迟到?
汤姆：我每次路过拐角,一个路标上面写着："学校----慢行."
DID YOUR DAD...
2)Tom call Jim's name:"I can't bear such a foolish!"
and Jim say:"You mother could (bear)!"
汤姆对着吉姆骂道:"我受不了你这个苯蛋了!"
吉姆说:"你妈妈能!"
附:bear 有两重意思:"生"和"忍受"这个笑话正是根据这点.
3)Tom call Jim's name:"I can't bear such a foolish!"
and Jim say:"You mother could (bear)!"
汤姆对着吉姆骂道:"我受不了你这个苯蛋了!"
吉姆说:"你妈妈能!"
附:bear 有两重意思:"生"和"忍受"这个笑话正是根据这点.
4)A man goes to church and starts talking to God.He says:"God,what is a million dollars to you?" and God says:"A penny",then the man says:"God,what is a million years to you?" and God says:"a second",then the man says:"God,can I have a penny?" and God says "In a second"
一男子进入教堂和上帝对话.他问:"主啊,一百万美元对你意味着多少?"上帝回答:"一便士."男子又问:"那一百万年呢?"上帝说:"一秒钟."最后男子请求道:"上帝,我能得到一便士吗?"上帝回答:"过一秒钟."
5)Mother sent Tommy to the store across the street to buy a good box of matches.When Tommy came back,mother asked him,”Did you buy a good box of matches?”
“Yes,Mum.”Tommy replied,”I have tried them all.”
一盒小火柴
妈妈让汤米去马路对面的商店里买一盒好用的火柴.汤米回来后,妈妈问他,“你买的是好用的火柴吗?”
“是的,妈妈.”汤米回答,“我把它们都试过了.”
6)Father:Uh,oh,I think I just made an illegal right-hand turn.
Susie:That is okay ,dad,the policeman behind you just did the same thing!
开车
父亲：哎呀,我刚才违规右转弯了.
苏西：没事,爸,跟在你后面的警察也这么转了.
7)Little Robert asked his mother for tow cents.”What did you do with the money I gave you yesterday?”
“I gave it to a poor old woman,”he answered.
“You’er a good boy,”said the mother proudly.”Here are tow cents more.But why are you so interested in the old woman?”
“She is the one who sells the candy.”
好孩子
小罗伯特向妈妈要两分钱.
“昨天给你的钱干什么了?”
“我给了一个可怜的老太婆.”他回答说.“你真是一个好孩子,”妈妈骄傲地说.“再给你两分钱.可你为什么对那位老太太那么感兴趣呢?”
“她是个卖糖果的.”
8)Ivan came home with a bloody nose and his mother asked,”What happened?”
“A kid bit me,”replied Ivan.
“Would you recognize him if you sew him again?”asked his mother.
“I’d know him any where,”said Ivan.”I have his ear in my pocket.”
他的耳朵在我的衣兜里
伊凡鼻子流着血回到家里.他妈妈问,“发生了什么事?”
“一个男孩咬了我一口.”伊凡说.
“再见到他你能认出来吗?”妈妈问.
“他走到哪里我都能认出他,”伊凡说,“他的耳朵还在我的衣兜里.”
9)Teacher:Here are two birds,one is a swallow,the other is sparrow.Now who can tell us which is which?
Student:I cannot point out but I know the answer.
Teacher:Please tell us.
Student:The swallow is beside the sparrow and the sparrow is beside the swallow.
两只鸟
老师：这儿有两只鸟,一只是麻雀.谁能指出哪只是燕子,哪只是麻雀吗?
学生：我指不出,但我知道答案.
老师：请说说看.
学生：燕子旁边的就是麻雀,麻雀旁边的就是燕子.

U＝220伏特,t＝1分钟＝60秒,Q1＝380焦耳,Q2＝180焦耳
对于在一分钟内产生的热量为380J的电阻R1,由　Q1＝(U^2 / R1)*t　得
380＝（220^2 / R1）*60
R1＝220^2 * 60 / 380＝7642.1欧
同理,对于另一个一分钟内产生的热量为180J的电阻R2,由　Q2＝(U^2 / R2)*t　得
180＝（220^2 / R2）*60
R2＝220^2 * 60 / 180＝16133.3欧
当这两个电阻串联后,接到220V电源上,它们在一分钟内产生的总热量为
Q＝[ U^2 / (R1＋R2) ] * t＝[ 220^2 / ( 7642.1＋16133.33) ] * 60＝122.14 焦耳

设原价为x
x×（1-5%）=34.2
x=36元

240

30次撞击声,说明火车经过了30-1=29根铁轨.每根铁轨25米,说明火车每分钟经过25x29 = 725m,折算成时速为,725m/min = 0.725x60 km/h = 43.5km/h,即该火车速度是 43.5千米小时.
如果,人与火车的距离是 L 米,根据题意可以得到：L/340-L/5200 =2 ,求出 L = 2x340x5200/(5200-340) = 727.57m.
即,此火车距离观察者大约 727.6米.

1.因为 I=U/R=220/20=11A
所以 Q=I的平方Rt=11的平方*20*60=145200J
2.因为电阻 电压 时间都一样,所以只需*2,即290400J

(1)均值和方差都是3
（2）概率为e^-2*3^2/2=9/2*e^-2
如果你在学概率论的话,这是最基本的题吧,课本应该都有.

正好正常发光说明电路中的电流是灯泡的额定电流I=P额/U额=1.5w/3V=0.5A,灯泡的电压等于其额定电压,UL=3V,电阻的电压UR=IR=0.5A*6Ω=3V
电源电压U=3V+3V=6V
一分钟内电阻消耗的电能W=UIt=3V*0.5A*60s=90J

我们的义卖会有许多吃的食物,有许多装饰的,有很多游戏,有的还做鬼屋,只要你有的是钱,有的是精力,欢迎你来临@!

一知半解呗!

泰然自若

要看作业的多少

3p 6*1/3*3=6
2p 3*2/3*2=4
so 3分机会大

let us play the piano togethe

解题思路：小数的加减运算，把小数点对齐再进行计算．小数的乘法，按整数的乘法计算，然后看因数共有几位小数，在积上从右往左点上几位小数点．小数的除法，先将被除数除数扩大相同的倍数，把除数变为整数，再按除数是整数的除法计算．

3.8+5.2=9 6.5×4=26 10-0.99=9.01
5.1÷17=0.3 0.25×8×0.4=0.8 1.25×80=100
13.9÷0.1=139 0.63÷21=0.03 2.8×0.2=0.56

点评：
本题考点： 小数的加法和减法；小数乘法；小数除法．

考点点评： 本题考查小数的加减乘除运算．

闭上眼睛一分钟后打开门
open是这个祈使句的谓语部分,one minute after是状语部分,after close eyes是闭上眼睛之后,one minute after就是表示在后项动作之后一分钟,因此就是如上翻译

就是物体通过这一段距离中平均的速度为2m/s.

按电路图,从电源正极出发.若是并联电路就先连干路,再连各支路,有电流表的就应当把将电流表串联在电路之中,最后将电压表被测电路两端并联即可,电键断开.
若是串联电路：按电路图,从电源正极出发.把各元件组成串联电路,最后将电压表被测电路两端并联即可,电键断开.

Is Jim younger than David?