6．两个相同的回旋加速器，分别接在加速电压为U1和U2、频率分别为f1和f2的高频交流电源上，现有两

函数y=-(4-x^2)^0.5(x 如果在一篇英语短文中,有一句话：He is（ ）father of four children.用a还是用the?前面没有提到father The child is the father of a 有没什么可以翻译的 工具? which man is their father? [ ]is their father? their＝ [ ] ____ our natural resources is very necessary.A.The most we make of B.The most we makeC.The most the ______of the scientist is a great loss to our country.选词:have trouble diong ;be essential for;be connected with;be angry;tell ...about...;more than ;agree to do ;correct order;death; sensible;probably;imagine从上面的词语中选择一个 Climbing hills is of great help to our health.为什么用of? 文献检索的途径和步骤具体如何? 《文献信息检索》名词解释1、信息检索策略2、搜索引擎3、信息检索4、倒排文档 there are forty-four students in class a.twenty-three of()are girls A.their B.them C.they the students of class four all are here today 改错 含有over的短语要大量的 20个以上 invite you over中的over是什么意思?和come over中的over一样吗 若x=-2是方程3x+4=x/2-a的解,则aˆ2012-1/(aˆ2012)的值为 函数y=根号下(4-x^2) (x≥-1)的曲线的长度是 已知函数f(x)=lnx,g(x)=2-3/x (x>0).(1)试判断当f(x)与g(x)的大小关系；（2）试判断曲线y=f(x)和y=g(x)是否存在公切线,若存在,求出公切线方程,若不存在,说明理由. 英语翻译求：Leader Of The Band 的中文翻译我的意思是问这歌的中文歌词的 The young like the band that has lots of e——————. 如果被减数,减数和差的合是200,减数和差的比为1：4,被减数,减数,和差分别是多少? 一张长方形纸,长25.12厘米,宽18.84厘米.用这张纸卷成一个圆柱.卷成的这个圆柱的底面积是多少平方厘米?急考虑两种情况 被减数、减数与差的和为200,差与减数的比为1:4,被减数、减数与差分别是多少? 用一张长18.84厘米,宽10厘米的长方形纸沿宽围成一个空圆柱,再配两个底面,这个圆柱的底面周长是（）厘米,高是（）厘米,侧面积是（）平方厘米,一个底面积是（）平方厘米,表面积是（）平 一张长方形的纸,长25,.12厘米,宽18.84厘米.用这张纸卷成一个圆柱.卷成的圆柱的底面积是多少平方厘米?(考虑两种情况) 用一张长25.12厘米、宽18.84厘米的长方形硬纸围成一个圆柱的侧面,加上底后,这个圆柱的容积最大是多少?急 食堂运进一批煤,如果用去这批煤的五分之二,剩下的比用去的多200千克,那么食堂原来运进煤多少千克? what is easy to get into but hard to get out of?55555555555555555 What is easy to get into but hard to get out of?（猜谜语） what is easy to get into but hard to get out of?这个谜语地答案希望准确 什么易进不易出?What is easy to get into but hard to get out of? The king 's military 缩写英文怎么写 Spell the word "English",____________. 1.They have 2 children.(改为同义句) _____ are four_____ in their family.2.Does he have a car?（改为同义句）_____ he _____ a car?3.She is studying in the classroom now.(用in the afternoon改写句子)She _____ in the classroom in the afte