题目

I wonder what it feels like to be one of          really rich . The Blacks already have three Rolls Royce and now they are buying          forth .     A．the ; a      B．/; a         C．the ; the    D．/; the   答案：A（2012•安庆模拟）已知a为如图所示的程序框图输出的结果，则二项式（2ax-1x）6的展开式中含x2项的系数是（　　）A．-6144B．192C．-6D．6144