— Do you know girl who is standing under tree?— Of course! She is Lucy my classmates.A.

问题补充：

— Do you know girl who is standing under tree?

— Of course! She is Lucy, my classmates.

A. the, the

B. a, a

C. a, /

D. /, the

答案：

(答案→)A. the, the

B. a, a

C. a, /

D. /, the

解析：冠词用法。the用于特指某人（物），本句意思就是指树下站着的这个女孩，girl, tree都是特指，故选择A。