题目

In the late nineteenth century, 5,000 pianos were sold in the United States each year and, with over half a million youths learning to play the instrument, there was a huge demand for sheet music （活页乐谱）．Indeed the demand was so huge that publishers rushed to enter the profitable market．During the last fifteen years of the century, many publishers began to set up shops in New York, the center for the production of the musical arts.        By the turn of the nineteenth century many important publishers had their offices on 28th Street between Broadway and 5th Avenue, and th5个乒乓球装一袋，每6袋装一盒．600个乒乓球能装多少盒？（用两种方法解答）