在活性污泥法污水处理场废水操作工进行巡检时，发现（）设施出现气泡或泡沫即属于不正常现象。
A.沉砂池
B.气浮池
C.曝气池
D.二沉池
参考答案：D
---What do you think of the man you have just interviewed?
---He gave me a(an) _________ that he was not very _______about the job.
A．expression; eager
B．impression; enthusiastic
C．idea; anxious
D．impression; interested
包装活动的管理是以商业包装为主还是以工业包装为主，要根据（）来确定。
A.商品特性
B.商品价值
C.销售要求
D.客户需求
