She is an girlA. eight-year-oldB. eight years oldC. eight-years-oldsD. eight-year-olds

问题补充：

She is an girl

A. eight-year-old

B. eight years old

C. eight-years-olds

D. eight-year-olds

答案：

(答案→)A. eight-year-old

B. eight years old

C. eight-years-olds

D. eight-year-olds

解析：英语中两个或几个单词中间由短横线连起来可以表示一个整体的含义，其中每个单词一般都是用原形。句意：她是一个八岁的女孩。故选A。