数列an中，sn=2an-1,数列bn满足b1=1,bn 1=bn an 1.证明an为等比数列

Is jane at school today?ji8 唐雎的外交语言特点 唐雎的"挺剑而起”是因为秦王的什么言行?请结合语句回答 朱自清的《春》赏析400字 朱自清的 中‘春花图’的赏析 200字左右! 朱自清的《春》读后感400字 摘抄和赏析 石有几种读法,分别是什么 圆柱和圆锥的侧面展开图形分别为_____. “石”有哪几种读音急需………………- 书上说有三种读音 the map is (on the wall).对括弧部分提问 Not students are at school today Tim is ill in hospitalNot () students are at school today .Tim is ill in hospitalA allB every C everyoneD other哪个为什么 Today is Suday,the student ( ) go to schoolA.can`t B.don`t C.mustn`t D.aren`t Who is the student _____was late for school today 朱自清《匆匆》中心思想不要太多 石有三个读音吗? Give you some colour to see see 隐形的翅膀的含义 一个圆柱和一个圆锥的底面积相等.圆柱的高6.28厘米,侧面展开图是正方形.圆锥高是2.4厘米,它的体积是多少立方厘米? 一个圆柱和一个圆锥的底面积相等.圆柱的高是6.28厘米,侧面展开图是正方形.圆锥 .一个圆柱和一个圆锥的底面积相等.已知圆柱的高是6.28厘米,侧面积展开图是正方形.圆锥高18厘米,它的体 who is [ ] [ ]today? [ ] am [ ]we all here? no who is not at school? I [ ] know. but i think heis.[ ] [ ] .He looks [ ] hie father.I see. 魔方里面有没有弹簧啊?拆过魔方的小伙伴们……刚买一个魔方,第一次玩,一不小心,抱着试试的想法,拆了,结果,瞬间掉了,装好之后,多了一个弹簧,但是装不进去了,谁知道的? He isn't at school today.I think he _____be willA.canB.shallC.mustD.should选哪个?为什么?不好意思,是be ill 杂拆二阶魔方 朱自清的《匆匆》有没有600字 this is a school,at the back of it is a moutain对不对 They are putting up a picture ---the front wall横线处应填什么介词 为什么?说清楚点可以吗? Today is the f_ day of the new term 光电耦合器检测方法分为哪几种? they _____ new blouses A put on B wearing on C are wearing D are putting on___ boat A the other B others C another D other 已知命题p,非p和p的否命题一样吗?分别和p同真假吗?命题p：正数的对数都是负数.非p和p的否命题分别是? 为什么“边边角”不能证明三角形全等