一道中学英文题!一.选择方框内适当词完成书信:writing,taking,sitting,playing,swmming,flying,sunny,studying,drawing,having.空白处填词语文章:DearBob,MynameisRich.I'minamiddleschool.Myschoolisniceandclean.There
数学推理和运算甲、乙两盒共有棋子108颗,先从甲盒中取出,放入乙盒,再从乙盒取出,放入甲盒,这时两盒的棋子数相等,问甲盒原有棋子多少颗?().A.40颗B.48颗C.52颗D.60颗1,0,9,100,().A.1
高三数列综合题已知函数f(x)=x²+x-1,α,β是方程f(x)=0的两个根(α>β),f'(x)是f(x)的导数,设a1=1,a(n+1)=an-[f(an)/f'(an)](n=1,2,.)(1)求α,β的值(2)已知对任意的正整数n,有an>α,记bn=ln[(an-β)/(an-α)](n=1,2,..