滴眼全面麻醉完全的药物是
A．丁卡因B．利多卡因C．布比卡因D．依替卡因E．普鲁卡因
参考答案：A
His wife is in bad condition now and he has to_____ a smiling face though heavy-hearted in the company.[ ]
A. give
B. offer
C. prefer
D. present
圆C通过不同的三点P（k，0）、Q（2，0）、R（0，1），已知圆C在点P处的切线斜率为1，试求圆C的方程．
