Last summer I took a course on _____ poisonous gases. [ ]

A. how to deal with

B. what to deal with

C. how to be dealt with

D. what to be dealt with

口腔健康教育的任务之一是

A．探索自来水含氟浓度
B．推广使用窝沟封闭
C．专业人员协助领导合理分配有限资源
D．控制含糖食品的食用次数
E．引起全社会对口腔健康问题的关注