indistinguishable
adjective uk/ˌɪn.dɪˈstɪŋ.ɡwɪ.ʃə.bəl/ us/ˌɪn.dɪˈstɪŋ.ɡwɪ.ʃə.bəl/
难以区别的，难以分辨的
impossible to judge as being different when compared to another similar thing
These forgeries are so good that they are more or less indistinguishable from the originals. 这些赝品很逼真，几乎没法将它们和真品区分开来。