_______ excited his parents most is that he had passed the entrance exam and was admitted into his dream college.
A.ThatB.WhatC.WhichD.It在线课程B
解析：
试题
分析：考查主语从句的引导词。本题的what引导起主语从句what excited his parents most.并在句中做主语。句意：让他的父母亲最高兴的是他通过了高考被心中的大学所录取。故B正确。考点：考查名词性从句
点评：名词性从句的考查集中在引导词的选择上，连接词that, whether, if在句中不充当任何成分，只起连接作用；
连接代词who(ever), which(ever), whom(ever),whose(ever),what(ever)在句中做主语，宾语，表语和定语；
连接副词when, why, where, how，在句中做状语。应从上下句的句法关系着手分析，切不可‘望句形生答案’总的来说，考生在解答此类型时，可用排除法或造句法，造句法就是仿造原句的语法功能仿造出一个易懂易理解的句子，帮助判断。