To create a aquatic ecosystem that is self sufficient, there should be a fish and a
a. snail
b. rock
c. plant
d. salt

Consider the model of the oxygen cycle on earth. the majority of earth's oxygen reservoirs are found in the a) atmosphere. b) biosphere. c) hydrosphere. d) lithosphere.

Approximately percent of the energy created by cell metabolism is used by the body to carry on its normal functions, such as respiration, digestion, reproduction, muscular movement, circulation, and cellular regrowth.

You and a group of friends are spending your vacation hiking through the mountains. it is cold in the mountains. you will be expending a lot of energy while hiking and you will need plenty of energy to keep you warm. you should pack foods high in to provide the most energy or kilocalories per gram of food. a) carbohydrates b) lipids (fats) c) proteins d) sugars