Т., в которых концентрация кремния в виде кремниевой кислоты и гидросиликата составляет не менее 50 мг/л.
"Free speech carries with it some freedom to listen." Warren E. Burger
"Honor is not the exclusive property of any political party." Herbert Hoover
"Hitch your wagon to a star." Ralph Waldo Emerson
"If fear is cultivated it will become stronger, if faith is cultivated it will achieve mastery." John Paul Jones