问题 问答题 简答题

在新建池塘养殖场时为什么要充分考虑养殖用水的水源、水质条件?

答案

参考答案:

养殖水源、水质条件对养殖场影响巨大,良好的水源和水质条件决定养殖的成败。养殖水源分为地面水源和地下水源,无论是采用哪种水源,应选择在水量丰足、水质良好的地区建场,水产养殖场的规模和养殖品种也要结合水源情况来决定。采用河水或水库水作为养殖水源时,要考虑设置防止野生鱼类进入的设施以及周边水环境污染可能带来的影响。使用地下水作为水源时,要考虑供水量是否满足养殖需求,供水量的大小一般要求在10天左右能够把池塘注满为宜。选择养殖水源时,还应考虑工程施工等方面的问题,利用河流作为水源时需要考虑是否筑坝拦水,利用山溪水流时要考虑是否建造沉砂排淤等设施。水产养殖场的取水口应建到上游部位,排水口建在下游部位,防止养殖场排放水流入进水口。

养殖水质直接影响鱼类生长,养殖用水的水质一般应符合《渔业水质标准(GB11607-1989)》规定,对于一些养殖水源的部分指标或阶段性指标不符合规定的,应考虑建设源水处理设施,并计算相应设施设备的建设和运行成本。

阅读理解
阅读理解。
     It was a beautiful sunny day. Miguel decided to go to the beach. He called his friends, but Mario was
at work, and Rosa was at her grandmother's home. So he had to go to the beach alone. He took his bathing
suit, towel, beach umbrella and his new boombox.
     When he arrived at the beach, there weren't many people. There was a family with two little children.
There were some American tourists at the shop. Miguel put up his beach umbrella and lay down. He
turned on his radio and began to enjoy the beautiful music.
     Soon Miguel went to sleep. While he was asleep, a man came and sat near him. He had a small radio
and it played same music as Miguel's. After a few minutes, the man picked up Miguel's boombox and
walked away. When Miguel woke up, his radio was gone, and the thief's little old radio was in its place.
1. What is a boombox according to the passage?
[ ]
A. A TV set.
B. A radio.
C. An umbrella.
D. A bed.
2. Who went to the beach with Miguel?
[ ]
A. Mario.
B. Rosa.
C. His grandma.
D. Nobody.
3. Put the following in the right order (次序) that happened.
   ① Miguel fell asleep.              ② Miguel lay down on the beach.
   ③ Miguel called his friends.    ④ Miguel got to the beach
[ ]
A. ①②③④
B. ③④②①
C. ②③①④
D. ②③④①
4. Miguel was a ______ boy.
[ ]
A. good
B. rich
C. careless
D. poor
5. What can we learn from the passage?
[ ]
A. We should look after our things well when we are out.
B. We should not take our radios out.
C. We should not sleep on the beach.
D. We should not sleep alone.
单项选择题