经过连续3年的走软,美国屋面工业似乎又重新开始获得活力,以新的面貌迎接2004年的到来。过去几年里,美国房产市场发展势头很好,新建住宅每年超过150万幢,二手房交易达到了创纪录的水平,这主要归因于美国相当低的利率。然而在商业工业建筑方面,就显得毫无生气,这是多种重要因素? After three consecutive years of weakness, the U.S. roofing industry seems to have regained its vitality and welcomed the arrival of 2004 with a new look. Over the past few years, the U.S. real estate market has enjoyed a good momentum with more than 1.5 million new homes being built each year. Record second-hand housing transactions have been attributed to the very low interest rates in the United States. However, in the commercial industrial buildings, it seems lifeless, which is a variety of important factors?