问题
选择题
Class regulations require _____ is the last to leave the classroom _____ off all the lights.
A．who; should turn
B．whom; shall turn
C．whomever; turns
D．whoever; turn
答案
答案：D
考查名词从句的连词和虚拟语气用法。主语从句中缺少主语，故用whoever="the" person who, require后接宾语从句，句中动词用（should）do。