I once watched one-act play, which was played by 11-year-old boy.A. a, aB. an, anC. a, a

I once watched one-act play, which was played by 11-year-old boy.
A. a, a
B. an, an
C. a, an
D. an, a

A. a, aB. an, an(答案→)C. a, anD. an, a解析：本题考查冠词。句中a one-act play泛指一场独幕剧；a 11-year-old boy泛指一个11岁的男孩。句意：我曾经看过一场独幕剧，是有一个11岁的男孩表演的。

就是这个解释