What benefits do nitrogen-fixing organisms provide in an ecosystem?
a. they release nitrogen compounds into the air
b. they convert nitrate into gaseous nitrogen
c. they turn atmospheric nitrogen into organic nitrogen compounds.
d. they eat organisms that contain large amounts of nitrogen compunds

Ausable water source is one that can be used by humans for drinking or agriculture. identify the water reservoirs as usable or unusable based on their current state. oceans rivers glaciers freshwater lakes groundwater

Matthew decided he wanted to hike up mount everest. on his way to the top, it began to snow and the temperature dropped to -10°f. matthew forgot to wear a heavy jacket so his body began to shiver beyond control. in this case, matthew's body shivering is the to a drop in temperature. * 0 points reflex stimuli responce environmental facto

Which kind of worm has a closed circulatory system? a planarian b fluke c pinworm d an earthworm