grass（不可数名词）草,草地，大麻；grasses表示多种类的草；grass（可数名词)告密者,揭发者。如：
Small things stirred in the grass around the tent. 一些小东西在帐篷四周的草丛里窸窸窣窣地动着。
In the old days, there were strict fines for walking on the grass or missing a study period. 过去，踩踏草坪或旷课都会被重金处罚。
The lawn contained a mixture of grasses. 草坪上生长着各种青草。
I started smoking grass when I was about sixteen. 我大约16岁的时候开始吸大麻。
His friends had begun to suspect that he was a grass. 他的朋友开始怀疑他是告密的人。
I know these grasses. 我认识这些告密者。
