专题三冠词
重难点精讲
考点精讲
命题点一不定冠词a, an的用法（2011年31题考查）
不定冠词通常用于单数可数名词前，a 用于以辅音音素开头的单词前，而 an 则用于以元音音素开头的单词前。经常在考题中出现的有：
A an apple an artist an aunt an Asian country an American girl
E a European country an egg an eight-year-old boy an eleven-year-old boy
I an idea an interesting story
O an orange an old man an outgoing girl
U a useful book a university student a UFO a usual story an umbrella an ugly man an uncle an unusual story an unhappy smile
特别记不规则：an hour an honest man
