A:①②④
B:①③⑤
C:②④⑤
D:①②③
Did you often talk with your friends in English?
已知等比数列{an}满足2a1+a3=3a2,且a3+2是a2,a4的等差中项.
(Ⅰ)求数列{an}的通项公式;
(Ⅱ)若bn=an+log21an,Sn=b1+b2+…bn,求使 Sn﹣2n+1+47<0 成立的正整数n的最小值.
关于我国地理位置的叙述,正确的是