63 Chihuahuas Rescued From Colorado Breeding Operation 2 'dumped Like Rubbish' In Avebury During Heatwave Bbc News

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缺失的数是31。分析如下：数列规律：这个数列的规律在于相邻两项之间的差值是2的幂次方。具体来说，7与3的差是4，15与7的差是8，以此类推。差值计算： 3到7的差是4.

Ray & Stephanie Derita Charged After 63 Chihuahuas Rescued