题目

已知平面区域D由以A（1，3），B（5，2），C(3,1)为顶点的三角形内部＆边界组成。若在区域D上有无穷多个点(x,y)可使目标函数z=x|my取得最小值，则m= A．－2       B．－1       C．1       D．4 答案：C ---Good afternoon, Mr. Brown________? ---Yes, he is at home. Come in, please. ---Thank you. A. Where is Jim                        B. Is Jim in C. Are you Jim’s father                   D. Does Jim like to go out