— Have you seen empty box?— Do you mean box you showed to me yesterday? I put it in your

问题补充：

— Have you seen empty box?

— Do you mean box you showed to me yesterday? I put it in your schoolbag.

A. a, the

B. an, a

C. an, the

D. the, a

答案：

A. a, the

B. an, a

(答案→)C. an, the

D. the, a

解析：第一次提到某物时，用不定冠词，又根据empty 的第一个音标为元音音标，故选an，当第二次再提到该物时，用定冠词the ，故选C