中文摘要：

图G的一度点称为G的叶子．证明了对G的生成树的叶子数最小值到G的生成树的叶子数的最大值之间的任何整数，G都有某个生成树的叶子数等于这个值．

英文摘要：

The clique-graph of a graph G, denoted K（G）, is the graph obtained by taking the cliques of G as vertices, and two vertices are adjacent if and only if the corresponding cliques have nonempty intersection. In this paper, we prove that if the clique graph of G is a bipartite graph, then the clique transversal number of G equals the clique independence number of G. In addition, we present a polynomial-algorithm to decided whether the clique-graph of a graph G is a bipartite graph.