Last Sunday was my birthday. My mother bought iPhone4 as birthday present for me.A. a; a

问题补充：

Last Sunday was my birthday. My mother bought iPhone4 as birthday present for me.

A. a; a

B. an; a

C. a; an

D. an; an

答案：

A. a; a

B. an; a

C. a; an

D. an; an

解析：此题考查不定冠词的用法。a用在辅音音素开头的单词之前，an 用在元音音素开头的单词之前。