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一棵树有2个4度结点、3个3度结点，其余是树叶，则该树中树叶的个数是______．
A.8 B.9 C.10 D.11

A.
B.8
C.9
D.10

【参考答案】

B设1度结点树叶为x个，由树的握手定理知
2|E|=2(2+3+x-1)=2×4+3×3+x(边数=结点数-1)......

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A.B.
C.(
D.(
E.(
F.(

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