It's warm today, _______ it is raining. [ ]
A. and
B. but
C. or
答案:B
牙龈结缔组中可见大量幼稚的白细胞,应考虑为()
A.急性坏死性溃疡性龈炎
B.遗传性牙龈纤维瘤病
C.维生素C缺乏性龈炎
D.炎症水肿型慢性龈炎
E.白血病性龈增大