要求他们帮忙打扫教室Askthemtohelpcleantheclassroom注：clean英[kli:n]美[klin]adj.清洁的;整齐的;新的;正派的;vt.（使）清洁;变干净;除去…的灰尘;使…干净;vi.清扫;[例句]Heworehiscleanestslacks,acleanshirtandanavyblazer.他穿着他最干净的便裤，洁净的衬衫和藏青色上装...