预约

Since 1999, China's north and south of the Yangtze River and its eastern region and the Northwest Territories, almost every year for more than 10 days of sustained strength, a wide range of extreme high temperatures.

自1999年以来，中国北部和南部的长江和东部地区和西北地区，几乎每年都超过10的保持强势，极端高温广泛天。

The frequency changer velocity modulation technology is technology and so on collection automatic control, micro electron, electric power electron, correspondence to a body high tech technology.

摘要变频器调速技术是集自动控制、微电子、电力电子、通信等技术于一体的高科技技术。