two

bi-, bin-
前缀含义：two; twice; doubly;
助记词：bicycle;
同缀词：biannual,biennial,bigamy,bilateral,binocular,biplane,bisexual

di-
前缀含义：twice, two;
助记词：digamy;di（two，twice）+gamy（婚姻，结婚）→第二次结婚→再婚
同缀词：diarchy,digraph,dilemma,dioxide,divalent

duo-
前缀含义：two;
助记词：[图片上传中...(850-maroon-diploma-large.jpg-575776-1514418321207-0)]
duologue;duo（two）+logue（talk）→两个人说话→对话，对白
同缀词：duodecimal,duotone,

dipl(o)-
前缀含义：double;
助记词：diploma;diplo（double）+ma→双层的→叠成双层的证件→学位证书，文书
同缀词：diplococcus,diplophonic,diplopia

850-maroon-diploma-large.jpg