第4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21题: [单项选择]{{B}}Questions 11 to 18 are based on the conversation you have just heard{{/B}} A. At the woman’s home. B. At a bus station. C. At a gas station. D. At a garage. 参考答案:D 答案解析:[听力原文]
W: Hi, Dan, would you please check my car It consumes more gas than usual these days. Besid
