问题补充：
My friend Mary is beautiful girl and girl everyone likes to work with.
A. a, a
B. a, the
C. the, a
D. the, the
答案：
(答案→)A. a, a
B. a, the
C. the, a
D. the, the
解析：此题很容易误选B，认为第一次提到girl用不定冠词，第二次提到就应该用定冠词。但是，句中第二次提到girl时并不是特指的，此句实为一省略句，补充完整是：My friend Mary is a beautiful girl and she is a girl everyone likes to work with.比较以下两句(第二个girl前用了定冠词，因为那是特指)：
For this he asked a girl, but the girl refused to answer him.
为此他问了一个女孩，但这个女孩拒绝回答他。
The other day he met a beautiful girl in the park and the girl smiled at him
