Question

一道改错题：

Should John resign and Henry succeed him, we would have had a more vigorous leadership.
Should为A处
succeed为B处
would have had为C处
more为D处

我感觉是C错 但是又说不出原因

请详细解答
题中有the ONE must be changed

Answer 1

应该是c处，将would have had改为would have 这属于if引导的虚拟条件句，对将来事实的假设，在非真实条件状语从句中，谓语动词按正常情况“后退一步”。也就是：
①与过去事实相反，在从句中用过去完成时形式表示。
②与现在事实相反，在从句中用过去一般时形式表示。
③与将来事实可能相反，在从句中用过去将来时形式表示。
主句中则用情态动词would, should, could 等加一个与从句一致的动词形式。
例：If I had come her yesterday, I would have seen him.
If I were a teacher, I would be strict with my students.
If it should snow tomorrow, they couldn’t go out.
四、注意事项
①if条件句中如有were, should, had，可以省去if，并使用倒装语序。
②在现代英语中if条件状与从句中的谓语动词如果是be其过去形式一般用were。