A:生物大分子(核酸、蛋白质等)
B:生物圈
C:细胞
D:生态系统
一 I have made great progress in spoken English since last year.
一 Well done! I am sure you'll be good at it soon.
已知an为等差数列,bn为等比数列,其公比q≠1且bi>0i=1,2,⋯,n,若a1=b1,a11=b11,则( )