Scientists offer a few theories as to why duplicative results may be so elusive .
科学家们提出几项理论来解释重现试验结果为何如此之难。
" I think the more important step should be to restrain the handsets with the duplicative codes in the network , but this is often complicated and hard to do , " he said .
她表示：“我认为，更重要的一步应当是限制拥有复制识别码的手机入网，但这通常相当复杂，也难以操作。”
For too long , the federal government allowed the american people 's hard-earned tax dollars to fund ineffective and duplicative projects , failing to leverage advances in technology to achieve savings .
