Consider the following tree:   Node 5 is a [ Select ] parent ancestor sibling child of node 3. Node 9 is an [ Select ] leaf internal node. Node 8 is a [ Select ] parent ancestor child descendent sibling of node 1. Node 3 is the [ Select ] parent sibling child descendent of node 8. Node 8 is a [ Select ] leaf internal node. Node 10 is a [ Select ] descendent ancestor sibling parent child of node 2. Node 1 is an [ Select ] child sibling descendent parent ancestor of node 6. The relationship beween nodes 10 and 9 is [ Select ] parent-child siblings they are unrelated . Node 9 is at level [ Select ] 1 0 3 2 of the tree. The height of this tree is [ Select ] 3 2 5 4 .      多重下拉选择题