题目

It is Sunday morning. Mr. Brown and his son, Bill, are in a big shopping mall (商场). Mr. Brown wants to buy a new dress for Mrs. Brown. Bill likes oranges. So his father buys two kilos of oranges for him, too. There are many things and many people in the mall. There are men and women, old and young. They all want to buy something there. The people in the mall are friendly. They will be glad to help you find what you are looking for.根据短文内容，判断句子正（T）、误（F）。【1】Mr. Brown and Bill are in a big shopping mall on Saturday morning.【2】Mrs. Brown wants to bu13．对于三个数a，b，c，用M{a，b，c}表示这三个数的平均数；用max{a，b，c}表示这三个数中最大的数．例如：M{1，2，3}=$\frac{1}{3}$（1+2+3）=2，max{1，2，3}=3，…解答下列问题：（1）填空：max{-2，-5，-3}=-2；（2）如果M{-2，x-1，2x}=max{-2，x-1，2x}，求x的值；（3）在同一直角坐标系中作出函数y=x-1，y=-|x+1|，y=-2-x的图象（不需列表描点），通过观察图象，填空：max{x-1，-|x+1|，-2-x}的最小值为-1．