题目

 The idea puzzled me so much that I stopped for a few seconds to try to _________.        A. make it out        B. make it off          C. make it up            D. make it over 答案：A8．若实数a、b、c满足b+c=5a2-8a+11，b-c=a2-6a+9，试比较a、b、c的大小．