Every boy and every girl----(be)very clever为什么填is呢是这样规定的吗

当“each(every)+单形名词 + and + each(every)+单形名词”结构应分做两个单独结构来看时,应用单形动词.
例如：
Each book and each paper is found in its place.每本书,每一份文件,都可在一定的地方找到.
Every hour and every minute is important.每一小时,每一分钟,都很宝贵.
有时可省去第二个each或every,例如：
Every man and woman has good reason to be proud of the work done by their farhers.