Which sentences of the followings are right about a binary tree's characterization: ( There are more than one correct answers ) 下列关于二叉树性质的说法正确的有:(多选)
A.
If a complete binary tree is a full binary tree, it will be possible that leaf nodes is not on the bottom level . 当一棵完全二叉树是满二叉树时,点不一定集中在最下面一层。
B.
The amount of external null nodes in a binary tree with at least one node equals to its amount of nodes plus 1. 一棵非空二叉树的为空的外部结点数目等于其结点数加 1。
C.
All degrees of nodes in a full binary tree are 2. 满二叉树的所有结点的度均为 2。
D.
The amount of nodes of a full binary tree with at least one node must be odd. 满二叉树的非空结点个数一定为奇数个。