这个句子从句中为什么是be,请明白语法的朋友帮忙细细解答一下,谢谢了AllthatCUNYdemandsisthatthesestudentsbediligentandclever.Admissionhasnothingtodowithbeinganathlete,orachildofanalumnus,orhavinga

Question

这个句子从句中为什么是be,请明白语法的朋友帮忙细细解答一下,谢谢了
All that CUNY demands is that these students be diligent and clever.
Admission has nothing to do with being an athlete, or a child of an alumnus, or having an influential sponsor, or being a member of a particularly aggrieved ethnic group—criteria that are increasingly important at America's elite colleges. Most of the students who apply to the honours programme come from relatively poor families, many of them immigrant ones. All that CUNY demands is that these students be diligent and clever.
批准与否跟学生是不是一名运动员，或者是不是校友子弟，或者有没有颇具影响力的后台，或者是不是某个弱势的民族社团成员，都毫无干系——而这些在美国的知名学府中已经日益成为重要标准。申请加入荣誉计划的学生大多数来自相对贫困的家庭，其中许多人都是移民。城市大学唯一需要的就是这些学生必须勤奋并且聪颖。
注：全段以及中文翻译如上

Answer 1

动词像“demand,request,order,suggest,recommend等表示“命令,要求,建议等",宾语从句中的谓语动词要用原型.（其实本身是Should+ Verb）,但Should常常略去