The workers have produced ____ cotton this year as they did two years ago. [ ]

A. as twice much

B. so much twice

C. twice so much

D. twice as much

大副的安全管理职责包括（）。

A.督促驾驶部全体船员遵守国家政策、法令

B.认真执行各规章制度和劳动纪律

C.落实各种安全会议提出的各项决议和工作要求

D.定期召开安全生产会议，布置、研究、检查安全生产工作