—What can I do for you ?—I want MP4 player for my daughter. She needs .A. a oneB. an one

问题补充：

—What can I do for you ?

—I want MP4 player for my daughter. She needs .

A. a, one

B. an, one

C. the, it

D. an, this

答案：

A. a, one

(答案→)B. an, one

C. the, it

D. an, this

解析：此题考查不定冠词的基本用法。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。One作为体代词，代替前文所提到的那类事物。