简述认识世界和改造世界的关系

若实数x,y满足不等式组：2X-Y大于等于0,X+Y-3大于等于0,3X+Y-8小于等于0.则3X-Y的最小值是? 不等式解法|x|≥(2/x)解集 按要求改写句子,急用!1.小弟弟真胖.(改比喻句)2.池塘的水真绿.(改比喻句)3.雪山顶上,蓝蓝的湖水透明极了.(改比喻句)4.这棵榕树茂密的枝叶向四面八方伸展.(改比喻句)5.在南极考察队员面前, 英语改写句子,急用I don’t know when i shall start the work （改为简单句）I don’t know when ____ _____ the workHis sister has been a nurse for five years.（改为同义句）His sister has ____ ______ a nurse for five years 一,改句子1.There isn't any milk in the giass(改为肯定句） 2.He is a doctor （改为否定句）3.Kate teachers English in the school.（改为同意转换） 4.There are three people in my family .How many people are there in your family.( 东海渔庄怎么样 东海渔福怎么样 （1）已知x^2+x-1=0 求2x^3+2x^2-2x+2的值（2）若（3x+1)^5=ax^5+bx^4+cx^3+dx^2+ex+f,则a-b+c-d+e-f的值是A -32 B 32 C 1024 D -1024(3)已知x^2-xy-2y^2-x-7y-6=(x-2y+A)(x+y+B) 求A,B的值（4）若A=（2+1）（2^2+1）（2^4+1）（2^8+1） 句子改写,1 it will be necessary for you to see a doctor.（改为一般疑问句,要求使用must）.我改为：Must it is necessary for you to see a doctor.2 is it necessary for you to make so much noise?（用have to进行改写）我改为： However,I would go futher to avoid staying on the superficial level of this issue.不知道这句是否OK,能有更地道漂亮的说法吗? 改写句子,All the lesson in your textbook are very important.You should memorize them.All the lesson in your textbook are very important.You should _____them ______ ________. 估计池塘中的鱼.先捕50条,做上记号,放回池塘.再捕100条,发现有了2条有记号.如果不能估计,写出理由只是一道数学题而已,不要考虑那么多不确定因素. 解几道计算题!一.（-5）x【（-86分之1减1又17分之8减5分之1）x17-（-5分之4）的2次方二.（-8分之7）除以（1又4分之3减8分之7减12分之7）三.（-1）+（-1）的2次方+（-1）三次方+...+（-1）的99次方+（ 求几道计算题的解,以90千米每小时的速度行驶的汽车,刹车后做匀减速直线运动,5S后停止运动.求1 汽车刹车时的加速度；2刹车后4S汽车的瞬时速度为多少m/s?一队伍长500m,行进速度为3m/s.为了传 ”黥“怎么念? 英语句子改写,谢1.To learn to play tennis is not difficult. ( )( ) not difficult to learn to play tennis 2.I saw that he was lying on the ground just now I saw ( )( ) on the ground just now 改写同意句谢了.Do you want to do some sigh tseeing?Excuse me,how can i get to the railway stationwe've got a new house.It has a big garden.Do you want to do some sightseeing? 野山蜂为什么能飞科学家不是已经证明他们不能飞吗,要简练一些的答案 杀人蜂 是非洲蜂和什么蜂的杂交种rtrtrtrtrt 一道应用题,谁能解出来?水果店运来一批西瓜,第一天卖出总数的40%,第二天卖出140千克,剩下的与卖出的重量比是1:3,这批西瓜共重多少千克? 黥、劓 这两个字怎么念是什么意思? 鸟类的体长包括尾长吗?孔雀那样的尾长不会计入体长吧? 阅读训练五 燕子燕子 燕子是雀形目燕科的1属.本属鸟类体小型,体长130～180毫米.翅尖长,尾叉形.背羽大燕子燕子是雀形目燕科的1属.本属鸟类体小型,体长130～180毫米.翅尖长,尾叉形.背羽大都 为什么列方程解应用题时重复利用一个条件会得到一个恒等式 英语翻译Although the 532 nm (green) wavelength has the lowest absorption in water,generating the 532 nm (green) or 355 nm (ultraviolet) wavelengths with harmonic single crystals from 1064 nm laser pulses reduces the laser pulse energy output by a 英语翻译The shear force V and bending moment M in a beam will usually vary with the distance x defining the location of the cross section at which they occur.When designing a beam ,it is desirable to know the values of V and M at all cross sectio 帮忙改写一下句子改成陈述句：小明说：“我要到赵刚家去还书.”2：把句子合成一个句子：妈妈叫我.我看电视.3：李叔叔退休了,办了一个场子,快到春节了,你给他选了一副对联是? 改写一下句子John came back from Japan and then he bought an expensive car.___ ___ ____back from Japan,___ _____an expensive car 忖 字的广东话如何读 “忖”读什么 “黥”字怎么读? 忖字怎么读?