简述水质标准中细菌总数的定义及卫生学意义。
题型：问答题 论述题
问题：
简述水质标准中细菌总数的定义及卫生学意义。
题型：问答题 论述题
用括号内所给单词的适当形式填空。
1. When I arrived at the park, I saw those children ______(play) foot
ball on the grass.
2. The headmaster asked us _____(not be) late for school.
3. Can you tell me how _____(get) to the Children Palace?
4. He will call you back as soon as he _____(come) back.
5. The Green family live in the ____(center) part of 
the
village.