—There aren’t any toys in our suitcase．Where have you put them?

—Oh, no．That old lady sitting next to us ______ have taken ours by mistake.

A．must

B．could

C．should

D．would

自动喷水灭火系统施工各工序应按施工技术标准进行质量控制，每道工序完成后，应进行检查，检查合格后方可进行下道工序。（）