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Users questions:1. Depth-first search traversal similar to the first root of the tree traversal, it uses the data structure is _________; breadth-first search traversal similar to the level of the tree traversal, it uses the data structure is _______.2. When all Results points have equal weight, with the construction of two nodesBinary tree only ________. Thank 7,777,771. Stack, queue 2. Degree 2 nodes and the node is 0, or only two nodes per layer