一道初中英语单选题求助
——Whatdidtheteachersayjustnow?
——Heaskedthestudents______.
A.whentheyhadcleanedtheclassroom
B.wheretheyhadspenttheirMayDayholiday
C.howlongtheyhavebeencollectigshells
D.iftheywouldtakepartintheskatingmarathonornot
感觉ABD都像对的