He looked as if he ______ the answer. [ ]

A. knew

B. had known

C. knows

D. has known

维修电工班组完成一个阶段的质量活动课题，成果报告包括课题活动的（）全部内容。

A．计划→实施→检查→总结

B．计划→检查→实施→总结

C．计划→检查→总结→实施

D．检查→计划→实施→总结