【正确答案】 C

【答案解析】冠词a，an和the均可以修饰单数名词。a和an意为“一个；当所修饰的词的第一个音节为元音时用an；the则特指已经提到或正在讨论中或说话者心目中所特指的事物，请注意下面例句中冠词的用法：An old man and an old woman lived in a small hut by a river near a forest．One day the old man left the hut and went into the forest to gather wood．The old woman went to the river to wash clothes．