题干
已知圆的方程为
，设圆中过点
的最长弦与最短弦分别为
、
，则直线与的斜率之和为( )
，设圆中过点的最长弦与最短弦分别为、，则直线与的斜率之和为( )
A：
B：
C：
D：
答案(点此获取答案解析）
B
⑴When do you eat breakfast?
A.It's warm and sunny.
⑵Can you make a snowman now?
B.No,it isn't.
⑶What's the weather like today?
C.I eat breakfast at 7: 15.
⑷What would you like to do?
D.No,I can't.
⑸Is it windy and cold?
E.I would like to go swimming.