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已知等差数列{an}和等比数列{bn}各项都是正数,且a1=b1,a2n+1=b...
已知等差数列{an}和等比数列{bn}各项都是正数,且a1=b1,a2n+1=b2n+1,那么,一定有( )
A.an+1≤bn+1
B.an+1≥bn+1
C.an+1>bn+1
D.an+1<bn+1
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