Which of the following sources of pollution decrease the oxygen level of water? select the two correct answers
a) toxic metals
b) radioactive substances
c) plant fertilizer
d) animal manure
e) gasoline

which of the following statements about flood migration is true?
a) it is cheaper to pay for repairs after flooding has occurred than to fund flood migration projects.
b) it is cheaper to fund flood migration projects then to pay for repairs after flooding has occurred.
c) minimal research has been done comparing the costs of funding flood migration projects to the cost of repairs after flooding has occurred.
d) it cost roughly the same to fund flood migration projects as paying for repairs after flooding has occurred

which of the following are challenges to implementing sub stainable framing practices? select two correct answers
1. increased erosion
2. increased labor costs
3. higher initial costs
4. increased need for fertilizer
5. lack of pollinating insects