一个英语语法问题shoulditbeafailure,asmanyexpertspredict,itwouldrankasoneoftheworstman-madedisasters.这句话should提前是什么语法现象,

Question

一个英语语法问题
should it be a failure,as many experts predict,it would rank as one of the worst man-made disasters.
这句话should提前是什么语法现象,

Answer 1

虚拟语气中省略if的倒装.原句应该是If it should be a failure,it would rank as one of the worst man-made disasters.As many experts predict 是插入语,不用管的.
其实have done也有相似的情况.如：Had I listened to your advice,I would have passed the exam.同样是把if 给省略了.