1、不定冠词a, an a用在辅音音素开头的词前 eg. a book, a useful book an用于元音开头的词前. eg. an apple, an hour 2、定冠词the 1)特指某人/某物 The book on the desk is mine. 2)世上独一无二的事物前 the sun , the moon, the earth, the sky 3)形、副最高级及序数词前 The third boy is the tallest of all. 注意： He is my...