Three-sigma rating system -A method of statistical quality control (SQC) used to describe, analyze and control the rated strengths of climbing gear.是什么意思_Three-sigma rating system -A method of statistical quality control (SQC) used to describe, analyze and control the rated strengths of climbing gear.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句