人们吃进的食物和吸入的空气都要通过的结构是( )
A:食道
B:咽
C:气管
D:鼻腔
The boy is only ______. Today is his _________ birthday.
(Ⅰ)求证:数列logman=2n+2,{an}是等比数列;
(Ⅱ)若bn=anf(an),记数列{bn}的前n项和为Sn,当m= 2 时,求Sn.