The correct answer is (b.) infiltration. Rainfall is to precipitation as groundwater is to infiltration. Precipitation is the release of the water from the cloud (evaporated water) in the form of rain and snow. Infiltration is a process in which the water from the ground enters the soil.
They are alike cause you need them to build upon like bricks.
Oxygen, neccessary for cellular respiration, is the answer. As oxygen becomes scarce, your cells begin to aerobically produce very little ATP, in effect fermenting and producing lactic acid.
Defects in transcription factors underlie some forms of cancer.
