说明：  运用前序和中序建造树运用前序和中序建造树运用前序和中序建造树运用前序和中序建造树运用前序和中序建造树
(use and the use of sequence tree before construction sequence and the sequence tree used before construction sequence and the sequence tree construction sequence and the use of the former China Sequence use tree before construction sequence and the sequence tree construction)