At each level of the food chain, what happens to about 90% of the energy? a) gained as energy b) lost as heat c) converted into unusable compounds d) excreted as waste

African penguins, which inhabit the coasts of southern africa, were classified as an endangered species in 2010. two significant threats to their survival are ecosystem damage from oil spills and overfishing by humans. overfishing depletes the food supply of african penguins. the best method to reduce the threat of overfishing would be to . the risk of oil spills could be reduced by increasing the use of , which should oil consumption. if an oil spill does occur, could be used to remove the oil so the ecosystem may more quickly recover.

Why does bubbling occur when vinegar mixed with baking soda

9. the history of life on earth is recorded in