直齿圆柱齿轮减速器

小明集邮比小强多8张,小强集邮张数比小明少5分之1.小明集邮多少张? 第一条：正实数X Y满足XY=1那么1/X~2+1/4Y~2的最小值是多少（X~2表示2的平方意思）第二条：设a,b是实数,且1/1+a - 1/1+b =1/b-a 则1+b/1+a =多少呢 人教版八年级上数学周报第9期答案今天要是中国教育学会中学数学教学专业委员会会报的 设a是实数矩阵,证明AX=0与A(T)AX=0同解,从而矩阵A与A(T)A的秩相等 f（x）dx的积分=x的平方+C,则（1/x的平方）f（1/x）dx的不定积分是 They are talking about the play now .(用yesterday 替换now改写句子) They are talking about an exciting TV play是否定句 They are talking about an exciting TV play.改为否定句.They _____ _____ about an exciting TV play. -We were talking about the new play________day,remember?-Yes,i enjoy it very much.A.the otherB.anotherC.someD.other 求解：It was things and people ___they remembered___they were talking aboutA.that that B.that whichC.which thatD.which which答案选D，为什么？ 这句话应用怎样的语气读?詹天佑经常勉励工作人员,说：“我们的工作首先要精密,不能有一点儿马虎.‘大概’‘差不多’这类说法不应该出自工程人员之口”朗读这句话的语气应该是：（ Parde?_________________?they were marching across the park while they were dancing and singing,exercise h__ make our body healthy and stong 设A,B均为三阶方阵,且｜A｜＝2,｜B｜＝5,则｜3AB*｜＝? 能写一下怎么做出来的吗? 设A,B均为3阶方阵,|A|=2,|B|=3,则|-3A‘B^(-1)|=? 已知线段AB被点分成2:3两段,同时又被点N分成4:1两段,如果MN=5厘米,求线段BN的长 a的4次方-4a的3次方y+4a的平方y的平方速度啊谢谢 试用秒表,尺子,人耳设计实验方案,估测声音在空气中传播的速度评估： 利用尺子和秒表测量声速,有什么办法? 寻一本能指示人生的哲学著作最近越来越迷茫了,找不到方向了,觉得活着没意思,不知道自己要做什么,不知道自己的人生目标在哪...昨天看完《贫民窟的百万富翁》,感觉好了点...现在想找点 设向量组a,b,c线性无关,求向量组a+b,b+c,c+a的轶 为什么一组向量转置后,组成的矩阵满轶这组向量就线性无关求证明 (1,2,1,3),(4,-1,-5,-6),(3,-3,-4,-7),(2,1,-1,0) 求向量组的轶和极大无关组 从直线外一点到这条直线所画的垂线的长叫做[ ] 垂线段:从直线外一点引一条直线的什么线?这点和什么之间的线段叫做垂线段?垂线段:从直线外一点引一条直线的____线,这点和____之间的线段叫做垂线段. 《真理诞生于一百个问号》中的三个事例内容上,写法上有什么共同点 5．设A为n阶方阵,且 ＝3,则 ＝（ ） A、 ； B、 ； C、 ； D、 设A,B是两个N阶方阵,满足条件AB=E,|A|=-5,则|B|= In the sequence 2,5,4,10,6,15,p,q,...What are the values of p and Set P consists of all the positive even integers less than 14,and set Q consists of all the positive multiples of 3 less than 21.Set R consists of all members that are either in set P or set Q.How many members of set R are even?(A) 6(B) 7(C) 9(D) 10( A,B 均为阶方阵,|A|= |B|=3,则|AB^-1|=() . 在真理诞生于一百个问号之后这一课中,三个具体事例中的“问号”各是什么?由此发现的真理是什么?快呀!明天就要交了,一会也该下线了. there were six people at the table ,and they asked waiter for __and__a two cups of tea;four coffee b two teas;four coffeec two teas;four coffees d two cup of tea;four cup of coffee哪个选择是对的?