----- for a long time,most of the crops in this area died fr

_____ for a long time,most of the crops in this area died from lacking water.A.Being no rain B._____ for a long time,most of the crops in this area died from lacking water.A.Being no rain B.There was no rainC.To be no rain D.There being no rainthere be 句型在此句中为什么做状语?for a long time 不是时间状语吗?为什么是独立主格结构的非谓语动词短语,所以be动词后面就应该加ing?