Sustainability means developing practices which protect the environment while also providing for human needs. which of the following changes should be made to achieve sustainable logging?
a. clearing land by cutting down trees instead of burning them
b. planting new trees to replace those that are cut down
c. replacing trees that are cut down with a single species
d. tilling the ground after cutting down trees to increase soil fertility

How energy flows through each level in this energy pyramid. is all the matter and energy from one level transferred to the next level?

Ascientist is investigating the effects of salinity on fish development. he places fertilized fish eggs in an aquarium that contains low salinity and observes their development. what factor would improve experimental design the most? place the fish eggs in the open ocean because that is the natural habitat include another aquarium that has normal salinity to compare to the low salinity aquarium include an aquarium that replaces salt with sugar to confirm that the effects are specific to salt grow algae with the fish eggs in order to provide adequate nutrients to the developing embryos

Why do the circulatory systems of land vertebrates have separate circuits to the lungs and to the rest of the body?