forest是可数名词。

Characterize the degree sequence of forests !指出森林的度序列的特征。The orchard is surrounded by spruce forest .该种子园四周有云杉林环绕。The forest remains a virgin territory .这座森林还是一片处女地。He walked through the gloom of the thick forest .他穿过茂密阴暗的森林。Prevention of forest fires is up to you .森林防火是你们的责任。The railway cuts through a primeval forest.铁路穿越原始森林。