1. protein
2. essential amino acids
3. complete proteins
4. incomplete proteins
Hazard symbols<span> or </span>warning symbols<span> are recognizable </span>symbols<span> designed to warn about hazardous materials, locations, or objects, including electric currents, poisons, and </span>radioactivity<span>. The use of hazard symbols is often regulated by law and directed by </span>standards organizations<span>. Hazard symbols may appear with different colors, backgrounds, borders and supplemental information in order to specify the type of hazard. Warning symbols are used in many places in lieu of or addition to written warnings as they are quickly recognized (faster than reading a written warning) and more universally understood (the same symbol can be recognized as having the same meaning to speakers of different languages).</span>