Entende-se por carta informal a missiva trocada entre pessoas com um relacionamento próximo e entre as quais existe familiaridade (parentes, amigos, colegas, etc.). São cartas que utilizam um estilo coloquial, apresentando o texto características de subjectividade.
Freedom of speech is a principle that supports the freedom of an individual or a community to articulate their opinions and ideas without fear of retaliation, censorship, or legal sanction. The term "freedom of expression" is sometimes used synonymously but includes any act of seeking, receiving, and imparting information or ideas, regardless of the medium used.
The answer is mineral deposits
Im pretty sure its the second one. In dense seawater