已知数列{an}的前n项和为Sn，且S2n-1=4n2-2n+1，则Sn等于（） (A)n2+n (B)n2+n+1 (C)4n2+l (D)4n2-2n
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The lady formed a friendship with the old shoemaker because________．
A. she had the heels of her shoes repaired by him
B. he did a good job to the heels of her shoes。
C. she went into his shop every few days to talk with him
D. he taught her all important piece of wisdom
A.businessB.moneyC.goodsD.shopping
A. business
B. money
C. goods
D. shopping
A.flyB.runC.travelD.go
A. fly
B. run
C. travel
D. go
A.liberateB.liquidC.limitD.lively
A. liberate
B. liquid
C. limit
D. lively
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