Some passengers were walking through “one of the big halls at Paris” Charles De Gaulle Airport ________ the whole roof fell down.A.whileB.as soon asC.whenD.after
网友回答
C解析据句意及主从句的意义关系来确定连词的选用。据句意应选择“当……时候”的引导词，when引导的从句其谓语动词可以是延续或非延续性动词；while引导的从句其谓语动词只能是延续性动词。句中的“fell”为非延续性动词，故选C。