It is strange that she---in the last exam A,should have fail

It is strange that she---in the last exam A,should have fail it is strange that he should have failed in this exam It is strange that she should have done it. It is strange that she should have done it.句中should是情态动词吗? it is strange that she should have failed to see her own sho / might fail in the exam worried him ; a :that he It is strange that he (should) have left withoutsaying doodb It is strange that he (should) have made a mistake.如果是虚拟语气sh 有人这样说：（It is strange that he (should) have made a mistake.他居 It is strange that she (should) be so rude.怎么会有should省略?还有的是 Helen might fail in the exam.She is quite down.--Oh,________ It was strange that she should have gone away without saying