答案：A
I have been teaching for over twenty years, but never _____ a girl as bright as Lily.
A．I have met
B．I had met
C．have I met
D．had I met
患者，女性，40岁，半年来觉下前牙龈增生，影响美观，偶刷牙出血。检查：见下前牙唇侧牙龈轻度增生，质地有弹性，色近正常，探及少量龈上及龈下结石。
若患者被确诊为“药物性牙龈增生”，则其牙龈增生程度与下列哪项因素有关（）
A.性别
B.服药剂量
C.血清和唾液中该药的浓度
D.牙龈原有的炎症情况
E.服药时间
