后面用is不是are，因为her hair为不可数名词
例如
Her hair is white and short, and she has three silver rings in each eyebrow.她的头发又白又短，每条眉毛上都有着三个银戒指。
is
例句：
Her hair is black and long.
句意：她的头发又黑又长。
hair 是不可数名词, 作主语时, 谓语动词用单数；原句是主系表结构
用作不可数时用is。hair这个词既可以是可数名词，也可以是不可数名词。hair作为不可数名词是“头发”的总称，是集合名词。例句：I’ll have my hair cut.我要去理发。hair作为可数名词，是指一根一根的“头发”或“毛发”。
例句：Look at this，a hair in my soup.看这个，我汤里有根头发
更多例句：
1、He still has a good head of hair.
他的头发依然很多。
2、Good Lord,what have you done to your hair!
天啊，你把头发弄成什么样子啦！
3、I like the way you've done your hair.
我喜欢你梳的发式。
4、What a difference!You look great with your hair like that.
真是判若两人！你梳这种发型显得太帅了。
5、Did she use to have long hair?
她过去留长发吗？
6、Mary's red hair always made her conspicuous at school.
玛丽的红头发在学校里总是很惹眼。
7、Did you see the length of his hair?
你看见他头发有多长吗？
8、Your hair could do with a cut.
你该理发了。
9、I think grey hair makes you look very distinguished.
我认为灰白的头发使你看上去很有尊严。
10、I must get my hair cut.我得理发了。
