作文：
AA：The following appeared as part of the business plan of the Capital Idea investment firm.
“Across town in the Park Hill district, the Thespian Theater, Pizzazz Pizza, and the Niblick Golf Club have all had business increases within the past two years. Capital Idea should therefore invest in the Roxy Playhouse, the Slice-o’-Pizza, and the Divot Golf Club, three new businesses in the Irongate district. As a condition, we should require them to participate in a special program: Any customer who patronizes two of the businesses will receive a substantial discount at the third. By motivating customers to patronize all three, we will thus contribute to the profitability of each and maximize our return.”
AI：Responsibility for preserving the natural environment ultimately belongs to each individual person, not to government.
数学：
1、一个矩形，四个点的坐标分别为（1，0）（3，0）（3，1）（1，1），求过（0，0）点的正好平分该矩形面积的直线的斜率
2、10！/（10-r）！>1000，r是一个正数，求满足条件的r的最小值是多少？
3、大人和小孩出席一个什么聚会，大人每人出20元，小孩每人出10元，一共有300人，共收4500元，问小孩多少人？
4、一个圆形的轨道，一个人走了300米后正好又回到了出发点，问一下哪些可能是轨道的半径？选项有150/pai,25/pai,还有一个，我没有选 | 
