concentration n.专注;集中;集合

concept n.概念;观念;设想

conception n.观念;概念

concern n.关心;关注;vt.涉及;使关心

concert n.音乐会,演奏会

concession n.让步;特许权;承认

conclude v.推断出;作结论

conclusion n.结论

concrete a.实在的,具体的;n.混凝土

condense v.(使)压缩,精简