greens当青菜讲时是可数名词还是不可数名词

greens当青菜讲时是可数名词而不是不可数名词，因为greens本身就是复数名词。

例如，青菜富含各种人体不可缺少维生素，所以多吃青菜有益于保持身体健康。

For example, greens are rich in all kinds of vitamins that are indispensable to the human body, so eating more green vegetables is good for keeping healthy.