题目内容：

she has short hair（变复数）答案是they have short hair 他们是把人变复数了,我把头发变复数行吗?
she has short hairs 他有好几根短头发可以吗?

优质解答

they have short hair.他们都是短发（表示发型不可数名词）.they have short hairs.他们有几根短头发（具体一根一根的头发就变成可数名词了）.she has short hair.意思是她是短发.如果说她有一根短头发,句子应该是she has a short hair.所以变为复数时不能改变意思,hair 表示发型,不能加S.