The foreign teachers here work hard and try his best to make the activities lively and interesting.                      A              B         C                D                                           

患者因高速公路车祸导致口腔颌面部严重创伤，急诊入院

若上颌骨确诊骨折，急救首先是（）

A.止血

B.复位

C.止痛

D.防治感染

E.保持呼吸道通畅及止血