The most important thing about cotton in history is ______ part that it played in _____ Industrial

Revolution.  [ ]

A. /; /

B. the; /

C. the; the

D. a; the

调度系统运行人员收到中调下发的预令后，应在（）内予以回复确认，如认为预令不正确或存在疑问，应当立即通过调度电话向值班调度员汇报。

A.半小时

B.一小时

C.两小时

D.三小时