Question

求解答过程：Do you know when the

Do you know when the Great Wall _______. had come into being D. came into being C. was come into being B? [ ] A

Answer 1

您好，虚拟语气情境下与现在事实相反的用法是
从句:
动词的过去式（be的过去式一般用were）
主句:would/
should/
could/
might
+
动词原形
所以答案应为：you
(should
know)
或者
you
(would
know)
另外提供另外两种虚拟语气不同情境的用法：
与过去事实相反
:
从句
:had
+
过去分词
主句
:would/
should/
could/
might
+
have
+
过去分词
与将来事实相反
:
从句:动词过去式，should
+
动词原形，
主句
:were
to
+
动词原形
would/
should/
could/