Food kept in refrigerator stays fresh much longer but once the food is taken out , it again spoils after some time from this we can conclude that _.

Explanation:

Bacteria become inactive when subdue into low temperature still remains alive

but once brougth out to a warmer environment, they become active and become to act on the food.

c.more precipitation,but only when emission levels.

the principles and empirical processes of discovery and demonstration considered characteristic of or necessary for scientific investigation, generally involving the observation of phenomena, the formulation of a hypothesis concerning the phenomena, experimentation to test the hypothesis, and development of a conclusion that confirms, rejects, or modifies the hypothesis.