您正在收听的是《科学在行动》，由BBC全球广播频道制作播出。You're listening to Science in Action, brought to you by the BBC World Service.你正在收听的内容来自2039航班上的飞行记录器,也就是人们叫做“黑盒子 ” 的那个东西.This is what you'd call the flight recorder of Flight 203...
大气中含有70%以上的氮气.The atmosphere consist of more than 70 % of nitrogen.这只是对威尔逊氮气云室的一种改进.It was an adaptation of Wilson's cloud chamber, filled with nitrogen gas.采气管得用氮气吹扫.Sample gas tubes are flushed with nitrogen....
The case - hardening or carburizing process is in wide use.表面淬火 或渗碳法应用十分广泛.Campus environment to achieve the " hardening, green, landscaping, clean up. "校园环境实现了 “ 硬化 、 绿化 、 美化 、 净化 ”.The material with high water is a new...