should such a disaster occur ,the damage would be incalculable

问题描述:

should such a disaster occur ,the damage would be incalculable
should such a disaster occur ,为什么不能用if such a disaster had occurred,或者had such a disaster occured

should such a disaster occur这句就是说,这是表示与将来相反的假设.表示与将来相反的假设,其原来形式就是:If such a disaster wereto/should occur,那么倒装的时候,就是should such a disaster occur.而你说的if such a disaster had occurred,这句话就是表示与过去想法的虚拟或假设,两者情况不一样,就不能这么变!如果还没明白,可以继续追问.没搞明白,表示与将来相反的假设是什么意思