each boy and girl; each boy and each girl

都是用单数三人称形式
1、each(every)+ 单数名词 + and + 单数名词,此时谓语动词用作单数,如：
Each boy and girl has come and will sign his full name before attending the ceremony.
2、each(every)+ 单数名词 + and + each(every) + 单数名词,此时谓语动词用作单数,如：
Each hour and each minute has its value.
最后,请注意,each of后的名词前须加the,如each of the soldiers（不说each of soldiers!）