Lucy is a girl from America.A. ten-years-oldB. ten-year-oldC. ten year oldD. ten years old

问题补充：

Lucy is a girl from America.

A. ten-years-old

B. ten-year-old

C. ten year old

D. ten years old

答案：

A. ten-years-old

(答案→)B. ten-year-old

C. ten year old

D. ten years old

解析：复合形容词的表达法的结构是：数字+名词（单数）+形容词。所以本题应该选B。