1) It is demanded / necessary / a pity + that…结构中的主语从句的谓语动词要用should 加动词原形， should 可省略。

句型：

(1)suggested

(2)importantthat…+ (should) do

(3) a pity

(1)suggested, ordered, proposed, required,　 demanded, requested, insisted; + (should) do

(2)important, necessary, natural, strange

a pity,　 a shame,　 no wonder

(3)It is suggested that we (should) hold a meeting next week.

It is necessary that he (should) come to our meeting tomorrow.

2)在宾语从句中的应用

在表示命令、建议、要求等一类动词后面的从句中。

order, suggest, propose, require, demand, request, insist, command, insist + (should) do

I suggest that we (should) hold a meeting next week.

He insisted that he (should ) be sent there.

注意： 如suggest, insist不表示“建议” 或“坚持要某人做某事时”，即它们用于其本意“暗示、表明”、“坚持认为”时，宾语从句用陈述语气。

The guard at gate insisted that everybody obey the rules.

3)在表语从句，同位语从句中的应用

在suggestion, proposal, idea, plan, order, advice等名词后面的表语从句、同位语从句中要用虚拟语气，即(should)+动词原形。

My idea is that we (should) get more people to attend the conference.

I make a proposal that we (should) hold a meeting next week.