第13题: [单项选择]深度为6的满二叉树中,度为2的结点个数为( )。 A. 31 B. 32 C. 63 D. 64 参考答案:A 答案解析:[解析] 本题要用到二叉树的两个性质定义:①二叉树的性质2:在二叉树的第k层上,最多有2k-1(k≥1,其中k为层数)个结点。本题中第6层的结点数=26-1=32个。这也是叶子结点最大数。②二叉树的性
第18题: [单项选择]The committee ______ the problem for a whole afternoon but they have not yet reached an agreement. A. has discussed B. has been discussing C. are discussing D. have been discussing 参考答案:D 答案解析:commitiee集合名词,后面的谓语用复数,现在完成进行时照应后文"they have not yet reached an agreement”