题目

M(3,0)是圆x2+y2-8x-2y+10=0内一点,过M点最长的弦所在的直线方程为（ ） A.x-y-3=0 B.x+y-3=0 C.2x-y-6=0 D.2x+y-6=0 答案：B 解析:设圆心为C,则C(4,1),∴, 所求直线斜率k=-1. ∴y=-1×(x-3)=-x+3. ∴x+y-3=0.—Are you pleased with what he has done? —Not at all. It couldn’t be _______. Why didn’t he put more effort into his work? A. any worse            B. much better             C. so bad                 D. the best