We have been told that under no circumstances ___ the telephone in the office for personal affairs.

A．may we use

B．we may use

C．we could use

D．did we answer

口腔颌面临界瘤包括（）

A.粉瘤

B.成釉细胞瘤

C.多形性腺瘤

D.鳃裂囊肿

E. * * 状瘤