The growth of part-time and flexible working patterns, and of training and retraining schemes, ______ more women to take advantage of employment opportunities.
【单选题】如图,用连续精馏塔分离由A,B两种组份混合而成的某二元理想混合物,已知加入的原料流量F=10kmol/h,原料中易挥发组分A的浓度为 X F =0.5(摩尔分率,下同) ,经过蒸馏操作,A组份大部分由塔顶流出,塔顶产品A的浓度为 X D =0.9,流量为D,塔顶馏出物中易挥发组分A的回收率为90%,则塔底残液中易挥发组分A的浓度 X W 及残液流量W 分别为