Consider the following tree:   Node 5 is a [ Select ] ancestor sibling child parent of node 3. Node 9 is an [ Select ] leaf internal node. Node 8 is a [ Select ] ancestor sibling descendent child parent of node 1. Node 3 is the [ Select ] descendent sibling child parent of node 8. Node 8 is a [ Select ] leaf internal node. Node 10 is a [ Select ] ancestor parent descendent sibling child of node 2. Node 1 is an [ Select ] child ancestor descendent sibling parent 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 2 0 3 of the tree. The height of this tree is [ Select ] 4 3 5 2 .      多重下拉选择题