Its renewed again and again by natural water cycle
MITOSIS is used to generate more cells. It is a kind of cell division that the new cells are identical.
Absorption of heat by breaking down hydrogen bonds
The answer is A. When a potent drug is discovered, it has to undergo animal and human trials to test it ADMET (Absorption, Distribution Metabolism, Excretion, and Toxicity) properties. Using tissue cultures to test drugs, such as cancer drugs, prevents the incidence of subjecting humans to the unknown adverse effects of the drugs before the drugs are determined to be safe for use.
