虚拟语气词：should介绍

    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
    It is　 (2)important　　　　that…+ (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.