It has been snowing, roughly every third day, for as long as I've had the flu.自从我得了流感以来，这段时间一直在下雪，大约每三天一场。The cloud might be snowing ethane snowflakes into methane lakes below.云层可能正在向下面的甲烷湖飘落乙烷雪.After it had stopped...
It was snowing hard by then.当时雪下得很大。After it had stopped snowing, we all went sledging.雪停了以后我们全去坐雪橇玩.Ordinarily It'should be snowing at this time of the year.按说这时候该下雪了....