题干
I have a pet, ______ name is Polly.
A：it's
B：it
C：its
D：my
答案(点此获取答案解析）
C
I have a pet, ______ name is Polly.
A：it's
B：it
C：its
D：my
x，焦点坐标为(－4,0)，(4,0)，则双曲线方程为( )．
