☆R00t:1 冷Leaf:6,8,9,10,11,12 &o internal vertices: 1.2.3. 4.5.7 .o the levels of 2, 3 are 1, the levels of 4, 5, 6,7,8 are 2 ☆ the levels of9.10.11,12are3。 .o The height of a rooted tree is 3❖ Root:1 ❖ Leaf: 6, 8, 9, 10, 11, 12 ❖ internal vertices: 1, 2, 3, 4, 5, 7 ❖ the levels of 2, 3 are 1, the levels of 4, 5, 6, 7, 8 are 2 , ❖ the levels of 9, 10, 11, 12 are 3 。 ❖ The height of a rooted tree is 3