There is evidence that the most damaging of the recent oil spills would have been prevented had cost-cutting measures not been instituted.
如果是倒装,正常应该是什么样子,迷茫了
There is evidence that +从句
从句:the most damaging of the recent oil spills would have been prevented (had cost-cutting measures not been instituted.)
(主语=the most damaging of the recent oil spills ,谓语:would have been)
条件从句:if cost-cutting measures had not been instituted. (原句省略if,把had提前做倒装)
整体结构:if.....had not been ...., ......would have been.......(从句过去完成式,主句用would+现在完成式,满足规律)