Which characteristic best distinguishes runoff and infiltration?
a. runoff involves condensation and infiltration involves evaporation.
b. runoff occurs over land and infiltration occurs underground.
c. runoff occurs during floods and infiltration occurs during drought.
d. runoff describes water movement and infiltration describes water storage.

Runoff occurs over land and infiltration occurs underground.

Explanation:

the nitrogen cycle provides nitrogen to the ecosystem from the atmosphere, ground and oceans. nitrogen is an important component of complex molecules such as amino acids and nucleotides, which lead to the creation of proteins and dna, the building blocks of all life. plants absorb nitrogen in the form of ammonium, nitrate ion and, on rare occasions, as amino acids. animals receive nitrogen necessary for biological processes from feeding on living or dead organic matter.

a compound light microscope is used to magnify objects in steps.  

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