The researchers then compared the chemical arsenals of their aliens with those of native North American plants, （4）►to see if superior (or, at least, unusual) weaponry was the explanation for the invaders' success.◄ Their hypothesis was that highly invasive species would have chemical weapons not found in native plants, and w________⑧ pests, parasites and other plants would therefore not have evolved any resistance to. The more benign aliens, by contrast, were predicted to have arsenals also found in at least some native species.

然后，为了弄清外来物种的成功入侵是否得益于“超级武器“（或者至少是超常武器），这两位研究人员将已知外来物种的“化学武器库”同北美土生土长的植物“化学武器库”进行了比较。他们推断，具有高度入侵性的物种拥有土产植物所缺少的“化学武器”，对这种化学武器，害虫、寄生虫及其它植物都不能产生任何抵抗力。相比之下，入侵性较弱的外来物种所具有的“武器库”可能至少同样存在于某些土产物种。