三一口语

降水量、降雪量如何测定? 测量降水量的基本仪器有雨量器和雨量计两种。雨量器是用于测量一段时间内累积降水量的仪器。常见的雨量器外壳是金属圆筒，分上下两...

Introduction English is a universal language that is spoken and understood by people all over the world. It is considered to be the official or se...