题干
— How far is your cousin's home from here?
— It's about two ______ drive.
A：hour's
B：hours
C：hours’
D：hour
答案(点此获取答案解析）
C
— How far is your cousin's home from here?
— It's about two ______ drive.
A：hour's
B：hours
C：hours’
D：hour
上有一点
，它到
的距离与它到焦点的距离之和最小，则点
是增函数（大前提），而
是指数函数（小前提），所以