这句里的if not 如何翻译呢?Researchers lately have begun to extend that forecast by decadesif not centuries.如题,谢谢了

问题描述:

这句里的if not 如何翻译呢?
Researchers lately have begun to extend that forecast by decades
if not centuries.
如题,谢谢了

研究人员最近扩大了预报的时间,即便不能提前一个世纪,最少也有十年.(意思是,现在可以提前很长时间,预报以后的事了.)

而不是

甚至