第26题: [单项选择]Some very rare drawings have been recovered for this exhibition through ______ research work in museums and libraries. A. plain B. minor C. assiduous D. flexible 参考答案:C 答案解析:句意:经过在博物馆和图书馆的苦心钻研,这次展览会上展出了一些极为罕见的画作。assiduous刻苦的;勤勉的;百折不挠的。minor较小的;不重要的;不严重的。