I lost key to the door yesterday. It was unlucky day for me.A. the; aB. the; anC. a; aD. a

问题补充：

I lost key to the door yesterday. It was unlucky day for me.

A. the; a

B. the; an

C. a; a

D. a; an

答案：

A. the; a

(答案→)B. the; an

C. a; a

D. a; an

解析：此题重点考查冠词的基本用法。不定冠词有a和an两种：a用于辅音音素开头的词前，an用于元音音素开头的词前。定冠词指双方都知道的人或事物。特指某（些）人或某（些）事物。