描写黄河的作文400字

求初三物理,化学,好的参考书!本人物理不是很好,求那种可以较大提高分数的参考书,本人目前物理考60分,总分90；化学不错,要那种可以拿高分的参考书!我们物理是沪粤版的,化学人教版的!最 1.已知等差数列中,a2+a6=2,a7+a9=16,求a4及a12.2.已知1/a,1/b,1/c成等差数列,求证:(a+b)/c,(c+a)/b,(b+c)/a也成等差数列. 3点45分,时针与分针的夹角是多少度?最好有过程的 （）的赤道 （）的两级 该怎么填啊, 这是小学二年级作业,怎么做 X＋56、45－X=45、0.12M=24、12×1.3=15.6、X－2.5＜11、 12＞a÷m、 ab＝0、 8＋X、 6Y=0.12等式有方程等式有：方程有： 62页计算题答案.63页第17,18,19题 请问苏教版六年级上册数学补充习题71. Which of the following is correct?A. Are the big nice apples? B. Are nice the big apples?C. Are big and nice the apples? D. Are the big apples nice? Of the following which is correct?A.how hard they worked B.how beautiful are the flowersC.what a clever boy is he D.how nice to see you is 急求解析Which of the following sentences is correct?A.In the teacher came B.In did come the teacher C.In did the teacher come D.in came the teacher应该选哪个,为什么是错的! Which of the following sentences is correct?A Only when you realize the gravity of the consequences (you can) be more serious about it .B Only when you realize the gravity of the consequences (can you ) be more serious about it .为什么选B不选Ao i 是虚数单位,复数1-3i/1-i i是虚数单位,复数(1-3i)/(1-i)的共轭复数是多少考察的是哪些知识点啊 从早晨7点半到上午9点半,钟表的时针转过多少度 从早晨7点半到上午9点半,钟表的时针转过多少度 72页答案有点着急了啊,十分谢谢了7b 初一下册英语课本后面的不规则过去式浙江省的 单词表后面的 那个 急用~ 英语小故事 初一下册水平 要是过去式 稍长点请在20130519三点前回答 钟表上的时针每分钟转过的角的度数是 已知二次三项式mx^2+5xy-2y^2有一个因式是3x-y,求m的值.不用整除法,要完整步骤. 已知函数f(X)=-(1/3)x^3+2ax^2-3(a^2)x(a不等于0）当a>0时求函数y=f(x)的单调区间和极值急 为了测定水的组成选用下列装置回答问题：(氢气用盐酸和锌制得) （1）为准确测定水的组成,为防止杂质干扰,正确的连接顺序为：已=>_________=> 丙；（2）乙装置的作用是 _____________ .（3） 用H2和CuO 反应的实验来测定水的组成,如图A所示.请回答下列问题：（1）实验中,用锌粒和稀硫酸反应制取（3）下列情况下,对实验测定结果一定没有影响的是①③（填序号）①相对CuO而言,H2是 Which of the following is NOT true about Britain?A.\x05It used to be a powerful imperial country in the world.B.It plays an active role as a member of European Union.C.It is a relatively wealthy and developed country.D.It used to be one of the superp 26.Which of the following is true about the Dreaming?A.It is performed to commemorate the Aboriginal ancestors.B.It has little significance for people todayC.It is a superstition about the power of the landD.It contains knowledge about the land 8.Which of the following about the Queen is NOT true?8.Which of the following about the Queen is NOT true?A.The Queen selects the Prime Minister and the Cabinet.B.The Queen symbolizes the tradition and unity of the British state.C.The Queen acts as a Which of the following is TRUE about the teaching building的意思 已知i为虚数单位 则复数1+2i/i-2的虚部为? 已知i为虚数单位,则复数i（2i-1）=? 求函数f(x)=(x-1)(x^2/3)的单调区间与极值点 设函数f(x)=x^3-x^2-x+2 求函数f(x)的单调区间和极值