很有挑战性的一道题一个边长为1的正方形,第一次将它对折,得到面积为1/2的长方形,第二次再对折,得到面积为1/4的长方形

a×bc=def
先看a和c a*c=f
1,2,3,4,5,6中
1*2=2 1*3=3 1*4=4 1*5=5 1*6=6 2*3=6 2*4=8 2*5=0 2*6=2
3*4=2 3*5=5 3*6=8 4*5=0 4*6=4 5*6=0
只有 2*3=6 3*4=2两组可以其余都用了重复的或者没有的数字
试用：ac为2*3=6
2×b3=de6的话 b只能是5才能进位成三位数代入5,2*53=106 错误
3×b2=de6的话 b只能是4或5才能进位成三位数代入,3*42=126错误3*52=156错误
试用：ac为3*4=2
3×b4=de2的话 b只能是5或6才能进位成三位数代入,3*54=162 正确
3*64=192 错误
4×b3=de2的话 b只能是5或6才能进位成三位数代入,4*53=212错误 4*63=256错误
所以正确答案只有 3*54=162

因为(0,1]上减函数
所以f(0)>f(1)
所以
√3/(a-1)>(√(3-a))/(a-1)
分类讨论
a>1时
变成√3>√(3-a)
有3-a>=0
3>3-a
综合得到 1

解题思路：

蹦极者整个运动过程中只有重力和弹性绳的弹力做功，蹦极者和弹性绳组成的系统机械能守恒。也就是动能和重力势能和弹性势能三者之和守恒。b点时弹性绳对人的拉力与人受到的重力大小相等，那么在b点之前，弹力小于重力，b点之后弹力大于重力，也就是说b点之前合力向下做正功，根据动能定理合外力做功等于动能变化量，b点之前动能增加，b点之后合外力向上做负功，动能减小。所以b点动能最大，C错。动能和质量速度有关，当速度最小时，动能最小。最低点c速度等于0动能最小，A错。绳子的弹性势能和绳子的形变量有关，弹性绳原长时弹性势能最小，b点不是原长，所以弹性势能不是最小，B错。弹性绳拉的越长，弹性势能越大，所以a点到c点弹性势能逐渐增大，也就是动能和重力势能之和逐渐减小，即蹦极者机械能逐渐减小。D对。

D

I think it'll be very challenging if I take sales as my first formal job.

学过物质的量吗?用物质的量,还要加参数,数学法强解.
原混合物：Fe FeO ZnO 33.4 / 2 = 16.7g
物质的量 x y z
还原后：Fe Fe Zn
物质的量 x y z 13.5g
由此可算得 y + z = (16.7 - 13.5) / 16 = 0.2 mol
可得不定方程：
56x + 72y + 81z = 16.7
y + z = 0.2
或不用差量法,直接得出方程：
56x + 72y + 81z = 16.7
56(x + y) + 65z = 13.5
二者等价.解此不定方程,可引入其他参数,也可就用y（或z）表示其他两个变量（最好不要用x,因题目问到“混合物中铁的质量”）
得
x = 23/560 - (9/56)z
y = 0.2 - z
则
(1)混合物中铁的质量 56x * 2 = (4.6 - 18z) g (0 < z < 0.2）
(2)混合物中氧化锌与氧化亚铁的质量比 z :y = (0.2 - z) :z (0 < z < 0.2) 应当给出z的范围
此题应该还有其他条件,但没有也没关系,当数学题来做.其实有很多化学题的本质就是简单的数学题,只要你敢写,写出来就是了.你也许会觉的这样很假,跟没做一样,但结果无疑是有道理的.
PS：请给出答案.
我悲剧

for the first time, is able to
Though he does such work for the first time, we are all sure that he is able to
do with it well.

I am a man full of energy and passion,and I like do challenging work and tasks.I am good at communicating with others especially and doing teamwork.It is my dream to enter into bank field,and I am very interested in investment bank.The two points are considered necessary in the work of an investment bank.It is a high starting point for me,and I will feel honored if I am admitted in your bank.
不好意思第一二个疑问是我大意了,第三个疑问用 in 和by 都可以,意思相近.

2N2H4+N2O4=3N2+4H2O
64 92
3.2 X
92/X=64/3.2
x=4.6
所以需要4.6G N2O4
（so eazy）

1.毕业后,她选择了一个具有挑战性的工作.
After graduation, she chose a challenging work.
2.当年,很多作家都一些做谋生,艰巨的工作赢得了别人对他们的尊重.
Then, many writers who do make a living, hard work earned them the respect of others.

(a^2)b+a+b^2>=3(（a^2)b*a*b^2)^(1/3)=3ab 即:(a^2)b+a+b^2>=3ab -----------------------(1) (ab^2+a^2+b)>=3(ab^2*a^2*b)=3ab 即:(ab^2+a^2+b)>=3ab -----------------------(2) 而(1)式中的等号成立的条件,(a^2)b=a=b^2 只能a=b=1,这与题目的条件矛盾,所以等号不成立 (a^2)b+a+b^2>3ab 所以:((a^2)b+a+b^2)*(ab^2+a^2+b)>3ab*3ab=(3ab)^2

（1）已知P1=10KW=10000W V1=nV=2*0.5m/s=1m/s
根据F1=P1/V1=10000N
已知G1=10*60kg*10N/kg=6000N
根据η1=G1/nF1=6000N/2*10000N=30％
∴G轮=20000N-6000N=14000N
已知F2=G总/n=（G2+G轮）/n=（5*600N+14000N）/2=8500N
∴η2=G2/nF2=3000N/2*8500N=17.65％
（2）已知F2=8500N V2=V1=1m/s
根据P2=F2V2=8500N*1m/s=8500W

要看你的心理承受能力了,有些像别人故意刁难、钱财得失等也是很有挑战性的,还有像工作操作、对生活的某些坚持都是啊.心理状态和心情以及当时的境况,都会影响你,也就是是否使你觉得是挑战的条件.

解题思路：（1）该原电池放电时，负极上燃料失电子发生氧化反应，正极上氧化剂得电子发生还原反应；
（2）原电池放电时，电解质中阴离子向负极移动；
（3）根据转移电子相等计算该元素的化合价、丁烷的质量．

（1）该原电池中，负极上丁烷失电子发生氧化反应，正极上氧气得电子发生还原反应，丁烷和氧气反应生成二氧化碳和水，所以化学反应方程式为2C₄H₁₀+13O₂═8CO₂+10H₂O，
故答案为：2C₄H₁₀+13O₂═8CO₂+10H₂O；
（2）原电池放电时，电子从负极沿导线流向正极，所以负极上聚集大量的金属阳离子，则电解质溶液阴离子向负极移动，故答案为：负；
（3）设金属的化合价为x，则根据得失电子守恒关系可得
3360×10−3L
22.4L•moL−1×4=
10.4g
52.00g•mol−1=x
所以可得x=3，
串联电路中转移电子相等，所以消耗丁烷的质量=

3.36L
22.4L/mol×4
6.5×58g/mol=1.34g，
故答案为：+3；　1.34．

点评：
本题考点： 化学电源新型电池．

考点点评： 本题考查了原电池和电解池原理，明确离子放电顺序及转移电子守恒即可解答，难度不大．

不可能.因为无论怎么换,他的金币和银币之和都是奇数.

1.As the doctor's recommendation, he is suggested to try something new and chanllenging when under pressure in order to vent the negative sentiment.（本文虽然说是“有压力的人”,但是用“有压力的”修饰...

(x-4)^4+11(x-4)^3+37(x-4)^2+21(x-4)-56

合同双方涉及的所有争议或分歧,不管是源于合同的建立,含义,执行,效力及其违反还是同其有关的都需按照国际商会的仲裁条例由双方各自委派的仲裁员组成的法庭仲裁解决.
或
对于合同双方来讲,不管是源于合同的建立,含义,执行,效力及其违反所的争议或分歧,还是与其有关的争议或分歧都需按照国际商会的仲裁条例由双方各自委派的仲裁员组成的法庭仲裁解决.

Parachuting means that people jump from very high places like aircraft,parachute tower,skyscraper,etc.with the parachute.It is thrilling and challenging,therefore is rated as the sport for the brave.

Challenging

IB is a course full of challenge. Not only very helpful in developing my ability of independent and critical thinking, it will also provides me a new horizon in international and cross-cultural communication. There can be a overall ability improvement by the training of IB course. Comparatively, original courses limite their attention on the knowledge fixed within the books, ignoring the cultivation of students' ability on actual practice. Since I found myself quite interested in analyzing dissertations, conducting experiments as well as writing reports and with a rather decent credit goes all through my journey of science course study, I do want to participate in the learning of IB course.

I am cheerful and lively personality,motivated for the cause,and willing to try new experiences.
I'm condescension and self-discipline.I have the courage to face the challenges and also Like engaged in challenging job.
As a young person,I will put my enthusiasm and ability to do my future work.

以小河为对称轴,作牧童A的对称点B,
以草地为对称轴,作牧童A的对称点C,
连B和C,交河于D,交草地于E,
A—›D—›E—›A就是要求的最短路线.
证明：由对称性,AD=BD,AE=EC
∴经过两点,线段最短.

上面的数平方后交换十位和个位就是下面的数 如 4*4=16 所以下面是 61
答案是 18
前面一个数除以后面那个数再乘以10
60/30=2 2*10=20
30/20=1.5 1.5*10=15
所以答案是 40/3 9/8

p=m/v 以单位体积为准 m=m沙＋m水 m沙＝v X h X p沙
m水＝v X(1-h)Xp水 带入p=m/v 得到 p＝(h X p沙 ＋（1-h)Xp水）＝ρ水+(1-ρ水／ρ沙）h

5=1

天黑请闭眼 你说的是那个电影吧
说实话 我也没太看懂 反正那个男的是有病,很象是有双重人格或是梦游

I am ready to accept the job having challenge

The claim mainly expresses that educationhas a responsibility to guide students to a field that will make more money.Asfor me,I will firmly disagree with such a ridiculous view that may greatlymislead current college students.Firstly,the substance of education is notabout creating wealth but promote the development of individual ability.Inaddition,study itself is a process of digesting knowledge,which tends tocreate more value than money.Also,lucrative careers may not be the interestedfields of the students and the competitive pressure could be much higher.
Atfirst,we should be clear about the fact that the substance of education isindividual development.Educational institutions are typical educatingorganizations that commit the function of educating.They are responsible forthe correct guidance of students to achieve their personal promotion withoutdistraction of fame and money.If education fails to support the students tobuild up healthy personal view,they may take it for granted that they have toget used to the society by sacrificing their own interest.The consequence isvery disastrous as they may give up their dreams and lose their variety whenthey grow up.Hence,the social environment could be extremely depressing,sothat crimes take place frequently.To sum up,the function of educationalinstitutions are encouraging students to pursue their dreams instead ofdiscouraging them.
Secondly,we should be noticed that the most valuable product of study is knowledge forsure,but not earning money.If we are forced to go to school only for thedesire for making money,the substantial significance of study is ruined.Studyshould promote the interest of students in specific fields and motivate them toinnovate.And this compulsion is expected to make them devote to their chosencareers,so that wealth is created.Study in a stiff way is highly harmful tothe enthusiasm of students in particular courses and damage their primitiveimpression.Therefore,they might be hard to contribute entirely to theirfuture careers,while social productive efficiency is weaken in this way.Inconclusion,the tutors in educational institutions should rather promote theinterest in study than turning the significant learning process into snobbishlyboring path.
Eventually,the concept of lucrative careers is being more abstract than ever before,because the competence in such careers is increasing and other fields need toattract them by improving their salaries.There is no need in focusing on theincome of particular areas,for the economic environment is able toautomatically adjust the average salary of each individual.The graduates shouldbe promoted to take part in careers that have few employees and are necessaryto enlarge the scale of personnel.They could make contribution to their nationthrough committing more significant jobs instead of choosing soundly lucrativefields.In return,the national organizations will surely reward them with theappropriate amount that they deserve to possess.By the way,the so-calledlucrative careers are majorly conflicted with the interested fields of thestudents.In these circumstances,students are often required to refrain theircreativity in their work,so that the efficiency and effectiveness of companiesare sure to abate.This is a scary loop that the benefit made by theenterprises could subsequently get lower and the general income of eachemployee will then decrease.Therefore,the idea of lucrative careers is only atemporary effective view and should not be well promoted.
Finally,we can conclude that the lucrative careers temporarily exist,and there it isnot necessary to add pressure of making money on the process of study.As ismentioned before,the main goal of learning is developing knowledge,which isthe real motivation of individual growth.Education,especially in theeducational institutions,is obliged to improve students’ interest on studyingparticular courses to emphasize that they are expected to contribute to theirnation.Conclusively,the educational institutions are not encouraged to urgetheir students to follow the general trends of selecting fields associated withcurrent lucrative jobs.My position can be derived from the mentioned contentsand directly proved by the passage written above.

没有B的位置,斜面长度一,讨论好多
不过基本办法是运动方程
b=1/2at2+S
a=(2gsingl)开方(t-(2l/gsing)开方)
a-b求极值(用导数)
大于0就行了
否则a落地速度-b当时速度,看起来简单点.
如果斜面可动的话还会好玩点

(1)
x1+x2>=10; x2+x3>=15; x3+x4>=25; x4+x5>=20; x5+x6>=18; x1+x6>=12
所有等式相加
2（x1+x2+x3+x4x+x5x+x6）>=100
minz=x1+x2+x3+x4+x5+x6>=50
(2)
x1+x2+x1'+x2'>=10; x2+x3+x2'+x3'>=15; x3+x4+x3'+x4'>=25; x4+x5 +x4'+x5'>=20;
x5+x6+x5'+x6'>=18; x1+x6 +x1'+x6'>=12
同样相加
2（x1+x2+x3+x4+x5+x6+x1'+x2'+x3'+x4'+x5'+x6'）>=100
minz=80(x1+x2+x3+x4+x5+x6)+120(x1'+x2'+x3'+x4'+x5'+x6')
=80(x1+x2+x3+x4+x5+x6+x1'+x2'+x3'+x4'+x5'+x6')+40(x1'+x2'+x3'+x4'+x5'+x6')
>4000+40(x1'+x2'+x3'+x4'+x5'+x6')
显然合同工越少越好啊,取x1'+x2'+x3'+x4'+x5'+x6'=0
事实上这很好理解,从题意中,合同工护士上班时间同正式工护士,但是报酬却要更高,合同工护士和正式工护士相比,根本没有优势,要她干什么?
当然不要合同工的护士啦

解题思路：（1）该原电池放电时，负极上燃料失电子发生氧化反应，正极上氧化剂得电子发生还原反应；
（2）原电池放电时，电解质中阴离子向负极移动；
（3）根据转移电子相等计算该元素的化合价、丁烷的质量．

（1）该原电池中，负极上丁烷失电子发生氧化反应，正极上氧气得电子发生还原反应，丁烷和氧气反应生成二氧化碳和水，所以化学反应方程式为2C₄H₁₀+13O₂═8CO₂+10H₂O，
故答案为：2C₄H₁₀+13O₂═8CO₂+10H₂O；
（2）原电池放电时，电子从负极沿导线流向正极，所以负极上聚集大量的金属阳离子，则电解质溶液阴离子向负极移动，故答案为：负；
（3）设金属的化合价为x，则根据得失电子守恒关系可得
3360×10-3L
22.4L•moL-1×4=
10.4g
52.00g•mol-1=x
所以可得x=3，
串联电路中转移电子相等，所以消耗丁烷的质量=

3.36L
22.4L/mol×4
6.5×4×58g/mol=1.34g，
故答案为：+3；　1.34．

点评：
本题考点： 化学电源新型电池．

考点点评： 本题考查了原电池和电解池原理，明确离子放电顺序及转移电子守恒即可解答，难度不大．

单枪匹马
自成一家
风吹草动
童话
散曲
圆规
丢三落四

白日依山尽,黄河入海流,欲穷千里目,更上一层楼.
白手起家
日薄西山
依山傍水
山穷水尽
尽心尽力
黄龙痛饮
河清海晏
入木三分
海阔天空
流芳千古
欲盖弥彰
穷山恶水
千家万户
里外受气
目不识丁
更新换代
上行下效
一目十行
层出不穷
楼台亭阁

决非机器翻译,纯属个人脑力劳动.
1.To attract high-end customers and latch them down:To attract high-end customers and latch them down by holding activities
which are interesting and challenging enough.And build up a long-standing as well as firm relationship gradually through these activities.
2.Provide a interactive flatform for patrons and customers:Through these activities,to provide a interactive flatform for patrons and customers with related service.
3.Provide excellent service for ptrons:To provide excellent service for ptrons and brew advertising plan for their brang name products with spectacular chances,do our best to help the patrons with their advertising task.
4.Attract high-end customers like EMBA by unprecedented activites.
5.Brilliant doings,joining of high-end customers and brand-name ptrons,media's attention.
6.Set up a long-time good partnership with patrons by these effort.
.终于搞定了呵!累死俺了.

正确
函数在x=0时无定义,间断.但是在0附近的极限是存在的且为1

You will absolutely overcome all the difficulties with your challenging character.

相对分子质量=12a/b.因为化学中把碳12原子质量的十二分之一规定为1.这好像没什么挑战性

翻译如下：
Although life for me is very challenging,but believe that I can do.

a challenging jo

"Their life is full of challenges."

She likes to work on exercises of great challenge.

因为木块在水中漂浮,所以F浮=G,F浮=p水V排g,G=mg=p木Vg
所以p水V排g=p木V木g,p木/p水=V排/V木
所以p木/V木=(V木-24)/V木=(V木-24-18)/(V木-24),所以V木=96cm3
所以p木=V排/V木*p水=(96-24)*1g/cm3=0.75g/cm3
(注意:有一些体积的单位没写,请自己补上)

证明：
令 y=x,f(2x)+f(0)=2f(x)f(x)
令y=-x,f(0)+f(2x)=2f(x)f(-x)
所以 f(x)f(x)=f(x)f(-x),
因为f(0)≠0,所以f(x)不恒等于零,
所以f(x)=f(-x),f(x)为偶函数.

0、-1、-0.5
分别每个除号后面的整体设为0,之后解方程就可以算出x
x=0
1+1/x=0 1/x=-1 x=-1
1+1/(1+1/x)=0
1/(1+1/x)=-1 1+1/x=-1 1/x=-2 x=-1/2=0.5

In the future, I want to study, work in a foreign country, because I think this is a very challenging thing.

我做过这题.
我找找,用偏微分方程组.
ode45求解.

1,A food- crop- protect project
2, A joint project
3, Purpose
4, Aims
5, collect reproductive material
6, improve communications
7, Securing over 95%
8, crop genetic crop information
9, $30 million
10, Seeds

解题思路：要解答本题需掌握：声音是由振动产生的以及声音能传播能量．

人在高声喊叫的时候，声音以波的形式传播，当传到积雪层时候能引起积雪层振动．
答：因为声音是由物体振动产生的，人在高声喊叫的同时，也引起了周围空气的振动，振动通过空气传递给了积雪层，往往会引起积雪层的振动，这样会引发雪崩的危险．

点评：
本题考点： 声音的产生；声与能量．

考点点评： 本题主要考查学生对：声音产生的条件以及声音传播能量的理解和掌握．

是这样的,这句话的意思是“海洋生物专家现在认为海豚和食人鲨之间的关系比我们以前认为的还要近.”
than had been previously thought其实是一句省略句,如果全说出来就是
"Experts in marine life say that there is a closer relationship between dolphin and man-eating sharks than EXPERTS IN MARINE LIFE had been previously thought."
现在你明白啦?其实就是把从句中的主语省略了,为什么可以这样省略呢?是因为和句首的主语重复了.