known number
Lead was one of the metals known to the ancient world.
铅是早在古代就已知的金属之一。
—— 柯林斯例句Mercury is a known poison.
水银是一种已知的有毒物质。
—— 柯林斯例句It is difficult to relate these results with any known cause.
很难把结果与任何已知原因联系起来。
—— 给力词典精选People usually infer an unknown fact from a known fact.
人们通常从已知的事实中推断未知的事实。
—— 给力词典精选The testimony consisted with all known facts.
证据与全部已知事实相符。
—— 给力词典精选