There is a column of numbers: A1, A2, A3 If A1 = 2, then a2007 is () A. 2007B. 2C. 12D. -1

According to the meaning of the question: A1 = 2, A2 = 1-12 = 12, A3 = 1-2 = - 1, A4 = 1 + 1 = 2; period is 3; 2007 △ 3 = 669; so a2007 = A3 = - 1

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