题目若2x=m2^{x}=m2x=m,2y=n2^{y}=n2y=n,则2x+y2^{x+y}2x+y等于( )A.2m+3n2m+3n2m+3nB.m3n2m^{3}n^{2}m3n2C.mnmnmnD.m2+n3m^{2}+n^{3}m2+n3知识点:同底数幂的乘法、幂的乘方与积的乘方章节:未标注