加急!_______THEY HAD TAKEN OFF THEIR SHOSE WERE THEY ALLOWED TO GET INTO THE LAB
问题描述：
加急!_______THEY HAD TAKEN OFF THEIR SHOSE WERE THEY ALLOWED TO GET INTO THE LAB
A.IT WAS NUTIL
B.IT WAS NOT NUTIL
C.UNTIL
D.NOT UNTIL
貌似正确答案是B 麻烦请给解释
答
选D Not untilNot until they had taken off their shoes were they allowed to get into the lab.意思是：他们不把鞋子脱掉的话是不被允许进入实验室的.因为后面是用的倒装“were they...”故前面应是否定倒装“not...