问题
单项选择题
V型滤池出水效果好、过滤周期长,它采用的是()滤料。
A.匀质
B.上层粒径大,下层粒径小
C.非匀质
D.上层粒径小,下层粒径大
答案
参考答案:A
V型滤池出水效果好、过滤周期长,它采用的是()滤料。
A.匀质
B.上层粒径大,下层粒径小
C.非匀质
D.上层粒径小,下层粒径大
参考答案:A
Passage One
What is happening to Barbados’s sugar industry
A.It is prosperous and stable.
B.It has vast expanses of deserted cane fields.
C.It uses cane fields as tourist attractions.
D.It stopped growing sugar 30 years ago.