题目

 A big earthquake __________7.1 on the Richter scale struck Yushu, knocking down buildings and causing more than two thousands people to lose their lives． A. measured                 B. measuring         C. to be   measured        D. measures 答案：B已知（1-x+x2）5=a10x10+a9x9+…+a1x+a0，则（a1+a3+a5+a7+a9）2-（a0+a2+a4+a6+a8+a10）2=-243-243．