it be +adj+that从句中从句的动词只能是原型吗？（是不是省略了一个should?)

it 后面应该是跟is or was 原型的情况应该是有should

1.在句型 "It is important (necessary, strange, impossible, natural) that .... " 中，that后面的从句中的谓语动词用：(should) + 动词原形。 如：
It's necessary that we should have a walk now. 我们有必要出去散散步。
It's natural that she should do so. 她这样做是很自然的。
It's important that we should take good care of the patient.
重要的是我们要照顾好病人。
2.在句型"It is a pity (a shame, no wonder, better) that .... "中，that 后面的从句中的谓语动词用: (should) + 动词原形。 如：
It was a great pity that you (should) have made so many mistakes in your math exercise. 太遗憾了，你居然在数学练习中犯了那么多错误
It will be better that she stay with her grandmother.
她和她的祖母在一起就好了。
3.在句型"It is suggested (requested, proposed, ordered) that .... "中，that 后面的从句中的谓语动词用：(should) + 动词原形。 如：
It was suggested that the sports meet be put off until next Saturday.
大家建议把运动会推迟到下星期六。
It is desired that we (should) get everything ready by tonight.
希望我们到今晚将一切准备就绪。
It was ordered that the medicine be sent there by plane.
命令马上用飞机把药送往那里.
(个人认为上面的第3种情况基本都要用虚拟语气，因为这里都是表示命令或要求，而第1和第2两种则视说话者要表达的意思决定。)