When an etching agent is applied to a metal surface in order to restore a removed serial number, the stamped area will dissolve at as the unstamped area.

answer; talc and gypsum;

answer: cellular respiration takes in food and uses it to create atp, a chemical which the cell uses for energy. usually, this process uses oxygen, and is called aerobic respiration. it has four stages known as glycolysis, link reaction, the krebs cycle, and the electron transport chain.