ThesmogarrivedintheY的精选

问题详情：ThesmogarrivedintheYangtzeRiverDeltaregiononNov.30，_________theairquality   in12citiesoutof25wasratedasseverelypollutedbyDec≯1   A．where   B．when   C．which  D．what【回答】A知识点：定语...