---How old is your cousin?- He is now.A. 15 oldB. 15 yearsC. 15 years oldD. 15 year old

问题补充：

---How old is your cousin? --- He is now.

A. 15 old

B. 15 years

C. 15 years old

D. 15 year old

答案：

A. 15 old

B. 15 years

(答案→)C. 15 years old

D. 15 year old

解析：句意：你的表弟多大了？他现在15岁了。表示年龄应用…years old ，故选C。