题干
__________is a dog, and __________name is Luckily.
A：It; its
B：Its; it
C：It; it's
D：It's; its
答案(点此获取答案解析）
A
__________is a dog, and __________name is Luckily.
A：It; its
B：Its; it
C：It; it's
D：It's; its
：
是集合A到集合B的映射，若
，则
（ ）