每个班级都有三条杠吗

已知数列an满足a1+3a2+3²a3+...+3（n+1)an=n²,求an通项公式 已知a 已知a 已知a0,求4a平方-12ab+9b平方的算术平方根 下列化学方程式中,不能用离子方程式表示的是（ ）A.B.C.D.预习遇到的题..感觉都对啊! 1又5分之2的分数单位是（ ）,有（ ）个这样的分数单位,再加上（ ）个分数分数单位就成为最小的素数. 谁有小学数学四年级下册的练习试题 已知五边形的五个外角的度数比1：2：3：4：5,求这个五边形五个内角的度数 1.最小的素数的倒数比最小的合数的倒数多（ ）% 2.（ ）/24=21/（ ）＝0．375＝（ ）％＝（ ）填分数3． 3个不同的素数的倒数的和是105分之a,a＝（ ）4． 若最小的自然数为a,最小的素数为b,最 什么和它的倒数之和是最小的质数 一根绳子截成两段,第一段儿长3/7米,第二段占全长的3/7两段相比,哪一个长? 帮忙批改托福作文If you are an employer,which kind of worker would you prefer to hire:an inexperienced worker at a lower salary of an experienced worker at a higher salary?When asked about hiring experienced workers with high salary or non-exp M1:=MA(C,5); M2:=MA(C,10); M3:=MA(C,30);{可以改成 M3:=MA(C,60);} 上:=MAX(M1,MAX(M2,M3)); 下:=MIN(M1那请问如果还要满足穿线阳穿出最高均线的部位不能小于3% 又怎么加进以上公式中.怎么我编的(C-MAX(M1,MAX(M2,M3)) 批改托福作文Preserving the past is a waste of time.The past decades have witnessed an ever-widening gap between the tradition and modernization,owing to the rapid acceleration of technology and development of the society.It is on one hand claim 选股公式A:=MA(C,5);B:=MA(C,20);T:=(A-B)/B*100; ;在同花顺选股平台上执行选股时 提示请输入具体条件请高手完善 托福作文求批改 Always telling the truth is the most important consideration in any relationship between people.Some people hold the opinion that if they cheat others,they will have advantages over others or they could take advantage from other 托福作文,Do you agree or disagree with the followingstatement?It is not necessary for university students to attend classes aslong as they can pass their examinations.写作Some people argue that it is ok for universitystudents to skip classes on A5:MA(C,5); A10:MA(C,10); A30:MA(C,30); A60:MA(C,60); A90:MA(C,90); A120:MA(C,120); AA:=MAX(MAX(A30,通达信选股公式,通不过,输出只能是一个条件,请您在修改一下. 我做作业的时候老是注意力无法集中,而且还一直犯困,然后去玩电脑就精神抖擞,您觉得百度过的答案我会选吗? 有关学习书法的作文,最好写出它的过程,400字左右,千万不要抄的,我要自己写.急 关于 我热爱书法的 作文 （500字以上）主要抓住练习书法时候情景、思想感情、动作、语言、神态来描写我从1年级就开始学习书法,至今学书法已有6年了,还曾经获得各种奖项! 学习书法过程的作文450字左右,快 求托福作文批改谁能帮我批改一下托福作文啊? 托福作文求批改独立写作：do you agree or disagree with the following statement:Parents should allow children to make mistakes and let them learn from them.我的作文：Parents’ education has always beenan important part I children’s 已知a、b分别是196,289的算术平方根,求多项式4a;-4ab+b;-2（a-b）+1的平方根. 已知ab分别是196和289的算数平方根,求多项式4a－4ab+b（2a－b）＋1的算术平方根 已知ab平行于cd ,直线ef分别交ab、cd于点e、f,∠bef的平分线与∠dfe的平分线相交与点p.且∠efp+∠fep+∠p=180度.请说明∠P=90度【讲解仔细点,否则看不懂】【谢了】 已知,AB平行CD,直线EF分别交AB、CD于点E、F,∠BEF的平分线与∠DFE的平分线相交于点P,求证：∠P=90°急 在四边形ABCD中,AB‖CD,AB⊥CD,∠AEB=∠CED.F为BC的中点,求证AF=DF=0.5（BE+CE) 在四边形ABCD中,AB平行CD,AB垂直AD,角AEB=角CED.F为BC的中点(1)求证:AF=DF(3种证法).(2)若角AFB=55度,求角BCE的度数 【高一数学】数列{an}前n项和Sn=-n^2+9n,bn=|an|设bn前n项和为Tn,求Tn 托福作文批改Learning by oneself or with a teacher?It goes with the saying that everyone is a piece of blank paper when born.We can not ignore the fact that we need teacher during our lifetime.For instance,as a infant,parents are our guide.Howev