题目已知1m−1n=1\frac{1}{m}-\frac{1}{n}=1m1−n1=1,则代数式2m−mn−2nm+2mn−n\frac{2m-mn-2n}{m+2mn-n}m+2mn−n2m−mn−2n的值为（ ）A.333B.111C.−1-1−1D.−3-3−3知识点：整式化简求值章节：数与式 / 整式
