I found it astonishing that he __________

问题描述:

I found it astonishing that he __________
A.would refuse to travel first time B.should refuse to travel first time
C.should refuse to travel first class D.should refuse to travel first train
WHY?should在这里是什么意思

这里是虚拟语气的用法,虚拟语气有一种情况:
在“It is + a.+ that…”句型中,that从句中谓语动词常用should +动词原形.这类形容词有important,necessary,essential,advisable,urgent,vital,desirable等.
这里的astonishing也属于这类形容词