carbon, hydrogen<span>, </span>oxygen<span>, </span><span>nitrogen</span>
The 4th one. Maintaining body temperature and cooling down
The cells of multicellular organisms become specialized for particular tasks and communicate with one another to maintain homeostasis. Specialized cells in multicellular organisms are organized into groups.
The nose, mouth, ears and eyes decide the entry of foreign particles. Little children mostly acquire it because mostly children put their hands or stick their tongues on nearby objects which are mostly infested with bacterias and pathogens, sometimes these particles are harmful and sometimes they aren't.
