关于健康教育的特点，描述正确的是（）
A.以疾病为中心
B.以单向传播为主
C.不注重反馈信息
D.侧重于改变行为
E.宣传对象较为泛化
参考答案：D
间歇曝气式活性污泥法曝气池的运行工序包括哪些（）。
A.进水
B.曝气反应、沉淀
C.排放、闲置待机
D.以上都是
A vessel is equipped with cross-connected deep tanks.In which situation should the crossconnection valve be closed?（）.
A.The tank lie above the waterline and are filled
B.The tank are partically filled with dry cargo
C.The tanks are partially filled with liquid cargo
D.The tanks are filled and lie below the waterline
