three-letterCOCA⁸⁶²¹⁸BNC⁹¹⁵¹⁷⁺⁸iWeb⁴¹¹⁰⁶Economist³⁴³¹⁸⁺³ 例句 A tax is unlikely because of America's aversion to that three-letter word. 美国人对“税”这个字一向反感，因此征收碳排放税是不可能的。 ecocn The letters are grouped into three-letter“ words” known as codons, meaning that there are64 of them. 这些字母可三个一组地组成“单词”，称为基码 codon，这样的基码总共有64个。 ecocn