口腔颌面部因炎症而引起的囊肿主要是()
A.根尖囊肿
B.粘液囊肿
C.舌下腺囊肿
D.始基囊肿
E.牙龈囊肿
参考答案:A
Please turn _____ the TV. I want to watch sports news.[ ]
A. off
B. on
C. of
D. down
报火警时应注意哪些事项?