题干
—Excuse me, how long can I keep the book?
—You can return it by the end of this month.
A：give it away
B：come up with it
C：give it back
D：lend it again
答案(点此获取答案解析）
C
和直线
，抛物线
上一动点
到直线
和直线
的距离之和的最小值是( )