题干
Miss Brown is a friend of ______.
A：Lucy's mother
B：mother's of Lucy
C：Lucy mother's
D：Lucy's mother's
答案(点此获取答案解析）
D
Miss Brown is a friend of ______.
A：Lucy's mother
B：mother's of Lucy
C：Lucy mother's
D：Lucy's mother's
满足约束条件
的最大值为（ ）
