She prims her thin lips after every mouthful of tea.

她每喝完一口茶都让自己的薄嘴唇带出严肃的表情。

Design requirements: the use of algorithms for network Prims minimum spanning tree to the text of the various forms of output spanning tree edges and their weights.

设计要求：利用Prims算法求网的最小生成树；以文本形式输出生成树中各条边以及它们的权值。