内详2小时之内回答可获得多附加的100分

The spirit of the boy dedicated to all men who living in our world toughly.
Blessing from God.
It is a wonderful day,the clear sky and cloud,the young people,the brilliant sunshine,the fresh air,and of course a totally new me.God bless you all.
各种“新”的含义是不一样的,参照各个宾语的英文定义来选择形容词,"new sky""new air"等说出去会让人不理解的...

∫(上x,下3)tant dt=f(x)-f(3)
f(3)=5,所以f(x)=∫(上x,下3)tant dt + 5

翻译为后者比较准确

你已经选择了电源和电流表.下面选择其他的.
电压表:估测待测电阻两端的电压值为6v,但考虑电压表读数准确问题（也就是说示数在2/3处比较准确）,答案为C.当然你也可能考虑到用3v的电压表能否烧坏的问题,这就要考虑电路的设计问题,该电路的滑动变阻器在闭合开关的时候必须在其最大值,以后试验时,为逐步调小电阻,所以就不用考虑这个了.
滑动变阻器：1000欧姆的调节起来不方便,不宜操作.所以应该选择20欧姆的.还有我在作题时,感觉串联电阻一般为待测电阻的2倍左右.分压电阻一般小于待测电阻,为电阻的一半左右.
你可以思考一下.
谢谢

上在这里是状语,向上

Q1：
冰的热解热377J/g.水的比热4.2J/g.
100g冰化成水要吸热：337*100=37700J
100g水50°降温到0度,要放热100*4.2*50=21000J /热量Q=mc（t0-t）/
所以即使水降温到0度,也只能溶解部分冰,最后还是冰水混合物,0度.
或根据热量平衡：（吸热=放热）
337*100+100*4.2*t=100*4.2*（50-t）
得t=-15.12,显然不可能,所以最后是零度.
Q2：
热量Q=mc（t0-t）即 热量=质量*比热*温差.
对,放热=吸热,都是水比热一样,质量一样,温度上升与下降一样才能平衡.
或根据热量平衡：
100*4.2*t=100*4.2*（50-t）
得t=25.
Q3：
根据热量平衡：
337*100+100*4.2*t=100*4.2*（100-t）
得t=5.12℃.
Q4：
根据热量平衡：
337*100+100*4.2*t=200*4.2*（50-t）
得t=3.41℃,显然不是零度了.

燃烧中的青春
秋风卷着落叶,飘然而下,望着那悠悠哉哉打着旋满天纷飞的叶,心中莫名的感慨.蓦然回首,十七岁的我们走过了怎样的花季.
我们在积累和磨练中逐渐成长,生活赋予我们的是五彩斑斓画面,青春的花开花落让我们不再寂寞.翘首回望.
我们在成长中学会了坚强.当生活的难题一次又一次压向我们,我们挺胸抬头的面对,我们含着泪,微笑着说：“生活考验着我们的意志!
“青春树上那朵坚强花绽放了.它懂得了忍耐,懂得了坚强,懂得了默默承担.
我们在成长中学会了自信.当自卑一次又一次左右着我们时,我们勇敢的拿起自己生命的调色笔,大胆的在生命的调色板上调出万紫千红得色彩.青春树上那朵自信花绽放了,它懂得了自信,懂得了抛弃自卑,懂得了挑战生活,挑战未来!
我们在成长中学会了拥有梦想.当失落与无助袭击着我们时,我们狂妄的撑起竹筏去远航,寻求生命的理想,有着梦想做翅膀,即使再大的风浪,我们也能远航.青春树上的理想花绽放了,它懂得了拥有梦想,懂得了每一颗心都有一双翅膀,要勇往直前的飞翔,没有到不了的地方……
青春,花开的季节,我们拥有了坚强,拥有了自信,拥有了理想,岁月如潮水,奔涌不息,如梦似烟的往事,播撒着它的芬芳.我们已踏过儿时温馨的时代,正编织着青春快乐的梦想,青春的我们,请以自强不息的奋斗精神去开拓,去进取,去创新吧!光辉得人生之路等待着我们去踩平,鲜花,掌声,笑脸装扮的成功,等待着我们去争取!年轻的朋友们,青春不说累,相信吧!生活因我们而更加精彩!

因为1130=6*180+50,而内角和为180的倍数
所以此内角=180-50=130
即内角和=7*180
由内角和公式可得,边数=7+2=9

10的几次方米的形式告诉我：-10电子云的大小 小行星带 恒星（太阳） 行星
10的几次方秒的形式告诉我：0脉动一次的时间 一天 一年 人的寿命 地球的年龄 银河系年龄

若为点光源,则产生的影子必为本影.
若非点光源,那么光线完全照不到的区域为本影区；有一部分光线可照到,一部分被挡住的区域成为半影区.

Oh my God,I can't believe that I won the lottery which worth 5 million.How should I use the sum of money?First,I will buy a big house.Second,I want a beautiful car.Finally,I will take investment.Thank God.I get a conclusion that everyone has a chance to meet Goddess of luck.

令g(x)=2ax-f(x)=2ax-(a-1/2)x^2-lnx
则g'(x)=2a-(2a-1)x-1/x
由于 2a-1>0时,lim(x→∞)g'(x)=-∞,故此时g(x)>0不可能恒成立
故必须2a-1

Cs>Rb>K>Ca>Na>Li>Mg>Al>Ti>Zn>Fe>Sn>Pb>Ni>(H)>Cu>Hg>Ag>Os>Ru>Ir>Rh>Pt>Pd>Au
以上就是各金属的大概顺序表,实际上,象Os,Ir,Ru,Pd,Rh,等副族元素的金属活动性相差很小,而且与具体反应条件有关．

1.what【宾语】 to【状语】do【谓语】
2.how【状语】 to【状语】 do【谓语】+名词/代词【宾语】
------------------------------------------
是省略句,主语被省略了.

(1)
f'(x)=1/x-ax+b
f'(1)=1/1-a+b=0
b=a-1
(2)
f'(x)=1/x-ax+b,把 b=a-1代入得
f'(x)=1/x-ax+a-1
=[-ax^2+(a-1)x+1]/x
=(ax+1)(-x+1)/x
推出
x∈(-∞,-1/a)∪(0,1)时,f'(x)＜0则f(x)是单调递减函数
x∈(-1/a,0)∪(1,+∞)时,f'(x)＞0则f(x)是单调递增函数
(3)
当c≥1/2,f(x)单调递增
f(x)max=f(c+1/2)=ln(c+1/2)-(1/4)(c+1/2)^2+(c+1/2)
f(x)min=f(c)=lnc-(1/4)c^2+c
当0＜c＜1/2,f(x)单调递减
f(x)min=f(c+1/2)=ln(c+1/2)-(1/4)(c+1/2)^2+(c+1/2)
f(x)max=f(c)=lnc-(1/4)c^2+c

这是改完的...:)
Yes,I like English very much,because English is lovely to me.Then,I can communicate with aliens.I feel very happy in English class.Though English is very difficult,I still like English.

1、等压吸热 qp=cp△T=1.01×(1000-300)=707kJ/kg
2、1-2的熵变等于1-3的熵变,故△s13=△s12=cpln(T2/T1)=1.01ln(1000/300)=1.22kJ/kgK
3、所以,等温放热为 qT=T1△s31=-365kJ/kg
4、循环效率 = 1-qT/qp=48.4%
5、循环净功 =48.4%×707=342.2 kJ/kg
由于空气的质量为1kg,故输出净功为342.2kJ.

写的挺清楚的怎么会不懂
a week in the life of
that night i had a dream. it took me to beijing 2008 Olympics. so i found myself outside chang cheng hotel, surrounded me was the packed high-rise buildings, restaurants, apartments. the traffic flow wasn't flowing, all the showy cars were jamed on this broad road, beeping at each other. I suddenly felt so lucky being brought into a modern world featured with so many features.
i waved at one taxi, it igored me, when it came closer i realised it was occupied. this is the thing with life. whenver you saw a bus or a train at a far distance you know you are not going to catch it but they always seems to be waiting for you patiently, once you started to run, they always suddenly pull out and leave you there panting. i think here i found the principle about life that it never offer you a straitforward journey, even in your dreams!
luckily enough, amoungst a dozen of people who are waiting for a taxi. a taxi driver stick his head out of the window and talked to me
"going somewhere?"
maybe it's my different looking attracted his attention, i had no time to hesitate, I hoped into the car
"olympic park please."
the driver, fourty, fifty, amiable looking, gave me an amused glance. i like these kind of drivers. he is the kind that would chat the way through with the passenger not the machanical ones that would only say a "thank you" when you pay them taxi fare.
"how long will it take to get there? i am in a hurry."
"it must be your first time in Beijing, taxi trips are never predictable here." He spoke with a funny chinese accent. i don't understand what he means but i believe i'll figure it out later. i looked out of the windows, suddenly a well-designed shopping mall appear so appealing to me "there used to be park there" the driver told me.
"few years ago a millionair turned it to a shopping centre, and then he became a billionair" i could sense his despair, but he, reluctantly still trying to maintain his sense of humour. "you know uh.. we have a saying 'do not twist your arm around their legs' it tells your all the philosophy about life, we are just powerless people."

i kept on looking. all i saw was people, lots of them. it somehow reminded me of australia's rabbit overrun in the mid-nighteen century. i now realise how forseeing china's one child policy is. soon we came onto a bridge, i assume over 1000 cars were gathered on the same bridge. we are completely immovable. "what happened there" i pointed to the array of sign saying "no through road"
"oh, they had shuted down all the traffics near the Olympic park to improve the quality of air for the athletes. but the more they do that the worse it gets bacause all cars have to go around, that means we emit more pollutants."
"Ha ha, you are smarter than the governors." i jokingly complimented.
"no way. you know sometimes when you are in serious trouble, you do stupid things not because you are stupid because you can't find a right way to tackle the problem."
it started to wind now, the sky getting yellower and yellower, something started to knock on the windscreen. "don't be scared its just the sand storm. when you get use to it you will find it's not a big deal." i kept on watching the blue being eaten away by the yellow, the elegant buildings being wraped in yellow and then the cars and then everything. The force of nature!
"the dessert is approaching us 20km each year. Someday, this city is going to turn to a dessert. they have been planting tree to fight them back but the trees just wouldn't survive out there. we have been the world's factory producing cheap goods for decades now it's the time to pay them all back."
i remember when i was young my grandpa used to tell me storys. i always settled in the sofa and listened to the boring long long agos. my favouraite was the one about the hunters. they love the forest because that's where their treasures were found. they used to go hunting and the forest never let them down. it always offered them the freshest food. once their hunger were satisfied they started to log down the trees. they built their houses, made their furnitures and passed on their generations. i can't remember what happened after. i guess their town was flooded and then again the trees grow back and then it started another cycle.
Back to my trip, the heat did not got away, i felt the sun was angry at us and trying to burn us to ashes. i didn't know what to do i looked out again, i saw a big LG logo printed on the side of a bus. Life is good. i was so anxious i turned on the radio, "carbonmonoxide content in air has reached to 36 ppm... a car crash has resulted in 7 deaths and 11 severe injuries 8 of them are babies." the sand is stilling floating savagely in the air making rustling sound. "i can't resist the heat, i am getting out, stop!"
i woke up in terror, the sun the sand the radio report the chinese accent still keeps resounding in my head. i sit up on my bed deadly staring out of the window. every thing is as good as it was. the sun gently touches my head with the same warmth. so comfortable. Mum is cooking me breakfast. "get up now! you are late for school." i had another look at the sky, it is bluer than ever. i sighed in a relief.
20分钟写的有很多错误担待

范文————
论个人利益与集体利益
常言道“舍小家而为大家.”这反映的是个人利益与集体利益的取向问题.其实,集体利益在任何时候都比个人利益重要,因为倘若为了个人利益而损害了集体的利益,就不可取了.就像陈小姐一样,倘若她能将BB车折叠好或多交1元得行李费,就不会导致车上数十人被迫转车.她的行为损害了公众集体的利益,是不可取的.所以在个人利益与集体利益面前,我们应首先孤寂集体利益.
其实在个人利益与集体利益这个问题上,古人已经给我们作出了一个好榜样.如大禹治水,三过家门而不入.大禹在接受了治洪水的命令后,就一直奋战在治洪第一线中,为例早日治好洪水,让老百姓过上安定的生活,他离开了他的家和妻儿,全身心投入抗洪治水,甚至三次经过家门口也没有回去看望家人.为什么大禹最终能治水成功呢?是因为他心系百姓,把老百姓的集体利益放在首位,抛弃了自己看望家人的个人利益,他舍小家而为大家,以大局为重.在个人利益与集体利益中作出了正确的选择.
在当代,也不乏这样的例子,任长霞,人们的好警察.他医生破案无数,为人民,为社会扫除课不少罪恶分子,时刻维持着社会的安定与人们的安全.她几乎是夜以继日地工作,她的时间都花在了破案工作上,极少休息,更不用说可以回家看望年迈的母亲和年幼的子女了.她为了人民的集体利益,为了百姓的安全利益着想,他舍弃了自己与家人的相处时间,甚至到最后牺牲了自己的生命,她舍弃了自己的生命,为的就是百姓过上安全安稳的生活.她为了集体利益而舍弃了自己的个人利益,受到了人们的爱戴.
相比之下,现在的某些官员为了自己的个人利益而损害集体利益,贪污受贿,损害人民的利益,他们的行为是可耻的.同样,陈小姐的行为虽然不算严重,但他也损害了公众的集体利益,这折射出了社会存在的不良现象,这不利于和谐社会的发发展.
“大河有水小河满,大和污水小河干.”如果集体利益也保不住,个人利益也难以保全,所以在个人利益也集体利益下,应该作出正确的选择.

y=√x√x√x=x^(1/2+1/4+1/8)=x^(7/8)
y'=[x^(7/8)]'=(7/8)x^(7/8 -1)=(7/8)x^(-1/8)

加Ba(OH)2,均产生有刺激性气味气体,并能使红色石蕊试纸变蓝,证明原来含有NH4+；
再加稀硝酸,沉淀不溶解的,证明含有SO4(2-)；
沉淀溶解并产生气体的,把气体通入足量的澄清石灰水,石灰水变混浊,证明原来含有CO3(2-)

已知：U1额＝10伏特,P1额＝10瓦,U2额＝9伏特,P2额＝5.4瓦
求：U串大,I并大,P并大
由公式　P额＝U额^2 / R　得
L1灯的电阻是　R1＝U1额^2 / P1额＝10^2 / 10＝10欧
L1灯的额定电流是　I1额＝P1额 / U1额＝10 / 10＝1安
L2灯的电阻是　R2＝U2额^2 / P2额＝9^2 / 5.4＝15欧
L2灯的额定电流是　I2额＝P2额 / U2额＝5.4 / 9＝0.6安
　（1）当两灯串联时,实际通过两灯的电流相等,所以这时电路中允许通过的最大电流只能等于0.6安,那么这时电路两端允许加的最大电压是　U串大＝I2额*（R1＋R2）＝0.6*（10＋15）＝15伏特
　（2）当两灯并联时,实际加在它们两端的电压相等,所以这时电路两端的最大电压只能等于9伏特,所以这时干路允许通过的最大电流是　I并大＝（U2额 / R1）＋（U2额 / R2）
即　I并大＝（9 / 10）＋（9 / 15）＝1.5 安
这时电路消耗最大功率是　P并大＝（U2额^2 / R1）＋（U2额 ^2 / R2）
即　P并大＝（9^2 / 10）＋（9^2 / 15）＝13.5瓦

你给出的词我全用上了!希望帮得了你!
A:Lunch time!
B:Oh!I am hungry.What shall we have for lunch?
A:What about send out for fast food?I really enjoy it!That's so convenience!
B:OK!I want to have pizza,burger and Coke!And you?
A:I want to have sandwich,kebab and salad!Oh,Coke too!
B:It seems that our main meal is very rich!
A:Yeah!How about having some snack before or after our meal?
B:Good idea!I really enjoy Guangdong Snack!
(After the lunch.)
A:I am full!I can't eat any more!
B:So am I.
A:I want to take some back home.
B:Do it!Wow!The litter and the packaging are here and there.Let's put them away!Hey!Don't use polystyrene and plasitc to pack your food!That's not good for you health.
A:Ok!

这是对的.for表示对象.of表示范围.区别：
30 percent of people.百分之30的人.这还是人这个范围中的30%所以是of.
different percent for different functions.不同功能的占比.这是for表示对象.不是范围,是functions,功能.

水可以吸收二氧化碳?!回答错误!二氧化碳在水中的溶解度和小!
一是避免集气瓶过热而炸裂,
二是可以接收燃烧产生的废渣,使其迅速冷却.
细沙也是可以,但效果没有水好.有时候用细纱

（1）f(x)=sin^2(wx+π/6)-cos^2(wx+π/6)=sin^2(wx+π/6)-[1-sin^2(wx+π/6)]=2sin^2(wx+π/6)-1
最小正周期=2π/W,所以W=1,所以f(x)=2sin^2(x+π/6)-1
（2）tanx=sinx/cosx=4/3,（sinx）^2+（cosx）^2-1,且x∈（π,3π/2）,sinx=-4/5,cosx=-3/5,
又f(x)=2sin^2(x+π/6)-1=2（sinxcosπ/6+cosxsinπ/6）^2-1
=（7+24√3）/50
“√”根号

我觉得应该是第一年到第五年的意思吧,
如果是五分之一的话,一般不是one fifth么.
我做了一份有关公司第一年到第五年的企划案.

let sb do 应该接动词的,alone不成,你可以换成
As sure as the sun rises tomorrow, I'll never leave u alone.
leave sb alone 是放任不管,还有就是像太阳升起这样的真理要用一般现在时
大概就这么多吧

你算错了,A32应该等于-7.Amn代数余子式是(-1)的m+n次方乘以除去m行n列的行列式的值.

也就是大床房嘛
用twin size bed或者queen size bed 都ok的

1、由BA⊥AO,故连杆BA瞬间平动,故Vb=Va=2ωr
由轮子的瞬心为：D点,则轮子的角速度：ω1=Vb/（R/2）=2ω
则：C点速度：Vc=√(Vb^2+Vbc^2)=2ωr√2
2、以A为基点.B的加速度为：ab=2ω^2r
以B为基点：ac=√(2ω^2r)^2+((2ω)^2r)^2=2ω^2r√2

我觉得这个.字幕有问题.
go out with sb.不是跟……出去,而是跟……约会的意思.
所以,这里的意思是：得了吧,你在跟那个人交往/约会!
所以用现在时的意思就是说他们两个正处于交往的状态.

出自寒山拾得对。 昔日寒山问拾得曰：　　世间谤我、欺我、辱我、笑我、轻我、贱我、恶我、骗我，如何处治乎？拾得云：　　只是忍他、让他、由他、避他、耐他、敬他、不要理他。再待几年，你且看他。 寒山云：　　还有甚诀可以躲得？拾得云：　　我曾看过弥勒菩萨偈，你且听我念偈曰： 老拙穿衲袄，淡饭腹中饱，补破好遮寒，万事随缘了。有人骂老拙，老拙只说好；有人打老拙，老拙自睡倒；涕唾在面上，随他自干了，我也省力气，...

自己找

写人的My father is a gentle man My father has small eyes,Wear a pair of glasses,looking more gently,the daddy's hair are not many, he said "the intelligent head does not grow hair",daddy does the management, but daddy usually ever not talk bureaucratically to others, therefore his personal connection is specially good,is the same as me.daddy speaks always extremely temperately,never say hit the person,curse at people are also few,calculated scolded people not to be big, although sometimes also can be angry for a longtime,but just only about one day,could no surpass in one day-long. He usually educate me that the person must to be honestly,friendly to other,and working diligently. This is my father, I love him forever. 建筑类：埃菲尔铁塔Eiffel Tower (Eiffel Tower, French: La Tour Eiffel) is a symbol of modern Paris, is a built in 1889 in Paris, France, Mars is located in the hollow structure of the square tower, 320 meters high. Eiffel Tower is named after its designer Gustave Eiffel Bridge Engineer. Strange unique tower design, is the world's masterpieces of architecture in the history of technology, French and Paris has become an important and prominent signs attractions. Eiffel Tower in Paris is located in the Central and Western, the left bank of the Seine Pro. Tower built in 1889, so in order to celebrate the 100th anniversary of the French Revolution and to meet and set up the Paris World Exposition. Eiffel Tower is divided into three塔座to the top of the tower from a total of 1711 steps, respectively, from the ground at 57 meters, 115 meters and 276 meters there is a platform built. It is said that the tower share to 7000 tons of steel, 12,000 metal parts, and 2.5 million connected with rivets. May 15, 1889, in order to give the ribbon-cutting opening ceremony of World Expo, the designer of the Eiffel Tower Gustave Eiffel himself on the French flag or tower 300 meters high, thus, it is of him in order to commemorate the French and Paris this One contribution, in particular, are still under the tower for him to shape a half-length statue. Until January 16, 2004, in order to bid for the 2012 Summer Olympic Games, Paris, France at the Eiffel Tower on the city specifically for the introduction of the Olympic preparations made, and the Eiffel Tower has become France's bid a "natural advertisement."

应该是11的平方也就是121吧
第一竖列第5个不应该是17啊,17应该放到第五竖列的第一个去

1.i am sorry,this problem i should consult my superior,i will reply you as soon as possible.
2.this is your seat,please.
3.do you willing to attend the investigation tomorrow?
4.sorry,it is no free to go out during the meeting.
5.this flower is for you,welcome you to beijing.
6.this is the location that you take photos.
7.it is glad you attend this conference, it is my honor to receive you.

碘和铝或锌反应
I2+2Zn=ZnI2
3I2+2Al=2AlI3
反应非常剧烈,只要滴加少量水就能引发反应；据说是火山喷发的效果!

挥发的溶质啊,水基本变化不大.所以质量分数小了

①题中隐含条件 为AB=2 即AB为长 这样 点A才能落在CD上设 A点落在线段DC上的点为A^(a,1)则 AA^ 的中点 在所求直线上 即 （a/2,1/2)在直线上又因为 折线一定与AA^垂直 且AA^得斜率为1/ak*(1/a)=-1 (*为乘以）a=-k 则 设y=kx+n 将（a/2,1/2) a=-k 带入得 y=kx+2分之（k方+1）
② 这一问离不开第一问 分两种情况讨论 ①当折痕靠右的一点落在AB上时此时 观察就可 显而易见 当折痕为BD时最长 为根5②当靠右一点落在BC上时 由第一问得出的方程 分别带入 x=0 x=2 时 求出两个关于k的点用距离方程 根下（X1-X2)的平方+（Y1-Y2)的平方 当k得绝对值最大时 距离最大 最大仍为BD 结果仍是 根5 所以 折痕最大值是根5
得出一个关于k 的方程当k得绝对值最大时 距离最大 最大仍为BD 结果仍是 根5

A
在弹性相同的情况下,弹簧的形变程度越大,弹性势能越大

1.多读你所想要的文学风格的人的作品（创造一个思维氛围嘛,就怕读太多了平时你说话成那样了.-.-)
2.有些词语,是他们那个时代的人常用的,就像非主流的文章典型词语就是什么“青春、浮光、香樟树、年华”.你注意看,那种风格的文章就有一些很常用的词汇短语,比如：
……了
……的
……罢了
……吧
当然,这个你可以自己在阅读中慢慢发现.
3、我个人觉得,你说得这种风格作品,都是有特定语言风格的.首先它们都很简洁,不像现代文字一样给人很罗嗦的感觉,也就是说语言要精练.其次,感情十分含蓄,也就是说主题、情感不要写的太直白（但如果你写的是高考作文我劝你还是写直白点保险）.最后,文字总体给人一种,有点萧索冷清的感觉（这个是我的个人感觉,不知道对不对）,可能跟时代有关,也可能是作者的思维批判性比较强.总之,丰富感情含蓄表达是很重要的.

溶解的本质是极性相同的物质之间的电子轨道杂化

地球仪的支架和底座是为了更好的摆放他.地球是运动的,是围绕地轴自转的,地轴就是穿过地心与地球球面交于南北两极点,并且倾斜角度是固定不变的为23度26分.你可以去观察所有的地球仪都是歪的,而歪的角度都一样.
所以才有了你说的支点在极点,更准确的说是用支架把地球卡起来,而卡住的位置就是极点是吧?
为了便于认识地球,人们仿造地球的形状,按照一定的比例缩小,制作了地球的模型——地球仪.它和地球在宇宙中的情形是一致的,不能随便改动.
另外,北极点在北冰洋上,不在陆地上,只有南极点才在陆地上,是南极洲大陆.

因为不存在这样的运动轨迹呀
将图中对应速度逆时针转动,相应轨迹的落点在BD点间
将图中对应速度顺时针转动,相应轨迹的落点在AD点间
所有BD点间的轨迹中D落点对应弦最长
所有AD点间的轨迹中A落点对应弦最长
比较可得A落点对应弦最长

(1)取一次就结束,即取到黄球,概率是：2/5；
(2)包括两种情况,取到2个红球或取到3个红球,概率P=3/5*3/5=9/25

应该选C.
由题意易得：(Vb^2-Va^2)/2a1=(Vc^2-Vb^2)/2a2
则要判断a1与a2的大小,只要判断分子的大小即可：
分子相减得：Vb^2-Va^2-Vc^2+Vb^2=2Vb^2-Va^2-Vc^2
=(Va^2+2Va*Vc+Vc^2)/2-Va^2-Vc^2
=-(Va-Vc)^2/2
因此,分子之差

Dear friends
The earthquake occurred so suddenly,the disaster damaged the number of people's homes,so that the number of people homeless.Wenchuan immersed in great sadness,rescue teams also were doing everything possible.Chinese people are enthusiastic donors to Wenchuan people the courage to rebuild their homes.
Best wishes!