、。
If the sun were to vanish, every living thing would die.
Literal
If-もし sun [subject-が] disappear-[conditional-たら], every living-things [subject-が] will-die [probably-だろう].
もし ('if, supposing') is a hypothetical adverb that pairs with conditional forms (~たら, ~ば, ~なら) — slightly less dramatic and more general than 万一, which flags the condition as remote and grave. あらゆる ('every, all') is a formal/literary quantifier that modifies nouns directly. The noun 生き物 ('living thing, creature') is a compound of 生きる ('live') + 物 ('thing').