选择正确的读音填空。
chèn chēnɡ
称____职 称____赞
(I)根据周销量图写出周销量P(件)与单价x(元)之间的函数关系式;
(Ⅱ)写出周利润y(元)与单价x(元)之间的函数关系式;当该商品的销售价格为多少元时,周利润最大?并求出最大周利润.
——Would you mind my opening the window?——___________ It's much too hot here.
出现成语“南橘北枳”现象的原因是( )
Jack, American teacher,is arriving at our school by car.