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下列图形都是由同样大小的五角星按一定的规律组成,其中第①个图形一共有2个五角星,...
下列图形都是由同样大小的五角星按一定的规律组成,其中第①个图形一共有2个五角星,第②个图形一共有8个五角星,第③个图形一共有18个五角星,…,则第⑥个图形中五角星的个数为( )
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A.50
B.64
C.68
D.72
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