He       you more help,even though he was very busy.

A．might have given

B．may give

C．must have given

D．might give

患者因前牙不美观要求改善就诊，查体见前牙区牙面有茶褐色着色，无牙体缺损。询问病史，患者幼年有高氟地区居住史

人体慢性氟中毒的表现为（）

A.氟牙症

B.神经系统损害

C.骨骼肌损害

D.肾脏损害

E.以上皆是