At what pH would 50% of Daphnia survive after 2 hours?
A. 2.5
B. 3.5
C. 4.5
D. 7.5
E. 8.5
查看答案
Farm raised salmon
A. are more genetically diverse than wild salmon
B. rarely escape from their holding pens
C. increase the water quality in the area in which they are raised
D. are often infected with parasites and sea lice
E. are kept at lower population densities than wild salmon
Eutrophication in surface waters of developed and developing countries is generally caused by
A. non-filtered power plants wastes
B. addition of bacteria
C. runoff of nuclear waste
D. runoff of pesticides
E. runoff of fertilizers
Defining characteristics of a wetland include
A. i
B. ii
C. iii
D. ii and iii only
E. i, ii, and iii
Which of the following would not be used to alleviate eutrophication in a lake?
A. applying herbicides to kill nuisance plants
B. planting rooted plants to increase O2
C. pumping oxygen into the lowest layers of water
D. introducing insects that eat certain nuisance plants
E. adding nitrates
微信支付 
支付宝支付