听力原文: Nokia warned that the U. S. slowdown is now extending to other economies, and said that is cutting into demand for Nokia's handsets, and for its growing mobile in frastrncture business. In April, a more optimistic Nokia said it was on course for a 20 percent sales growth this quarter. That forecast has been cut in half. Tuesday's warning knocked a whopping $31 billion off Nokia' s market cap. Nokiajoins rivals Motorola and Ericsson in warning about sales. The rate of new phone purchases has slowed dramatically in Em'ope, with customers reluctant to trade up to new handsets. Why has the rate of new phone purchases slowed in Europe?