MostAmericanmagazinesandnewspapersreserve60percentofthe...
问题详情：MostAmericanmagazinesandnewspapersreserve60percentoftheirpagesforads.TheNewYorkTimesSundayedition__51_____maycontain350pagesofadvertisements.Someradiostationsdevote40minutesofeveryhourto__52__...