进行口腔健康促进的高危人群途径()
A.乳牙龋充填
B.控烟、戒酒
C.对有深窝沟的儿童进行窝沟封闭防龋
D.自来水氟化防龋
E.老年人牙齿脱敏
参考答案:C
It was after he got what he had desired ______ he realized it was not so important.
A.that
B.when
C.since
D.as
外鼻静脉的特点是()
A.主要经内眦静脉和面静脉汇入颈内静脉
B.面部静脉无瓣膜
C.面部静脉有瓣膜
D.血液只能单向流动
E.血液可以双向流动