Friday, September 16, 2022
问题:腐殖质不是一种纯的化合物,而是代表一类有着特殊化学和生物本性的,构造复杂的高分子有机化合物。
Friday, March 15, 2024
问题:沉积物内含有丰富的磷,但若不施人为作用,就不能很好发挥作用。
Saturday, November 25, 2023
Friday, March 15, 2024
问题:按照阿列金分类法,海水一般是()型水,淡水一般是()型水。
Thursday, January 18, 2024
Friday, March 15, 2024
Wednesday, May 3, 2023
Sunday, September 11, 2022
Thursday, January 18, 2024
问题:放养前进行石灰清塘,为了确保清塘效果要使水质和底质的pH值都必须大于()。
Wednesday, March 29, 2023
Friday, September 16, 2022
问题:水生动物排泄废物中含较多磷。浮游动物排泄磷酸盐常常是有效的重要的再生途径。
Friday, September 1, 2023
Friday, September 16, 2022
Monday, January 23, 2023
问题:当温度、压力一定时,水中含盐量增加,会使气体在水中的溶解度降低。
Friday, September 16, 2022
Friday, September 16, 2022
Monday, September 12, 2022
Wednesday, January 3, 2024
Monday, September 12, 2022
Monday, September 12, 2022