习惯用语fall into a decline1.开始衰落, 衰弱下去; 体力衰退(尤指因患肺病而衰弱)sink into a decline1.开始衰落, 衰弱下去; 体力衰退(尤指因患肺病而衰弱)on the decline1.走下坡路, 在衰退中the decline of life1.晚年, 暮年特殊用法autumn decline1.秋衰, 秋落citrus decline1.柑桔衰退病harmonic decline1.谐和衰减hyperbolic decline1.双曲型衰减technical decline1.由市场供求等内部因素引起的跌价decline in production1.生产衰退