Itiswellknownthat...众所周知……
Itisannouncedthat...据宣布……
Itisbelievedthat...人们相信……
Itisunderstoodthat...自不待言……
Itmustbepointedoutthat...必须指出……
Itmustbeadmittedthat...必须承认……
Itdoesn'tmatterwhethershewillcomeornot.
Itmakesnodifferencewhereweshallhavethemeeting.
Itsuddenlyoccurred22toherthatshehadforgottentolockthedoor.
当that引导的主语从句出现在疑问句中时,宜用it作形式主语,而把主语从句后置。
Isitpossiblethattheymaycompletethetaskaheadoftime?
Doesitmattermuchthathewon'tbeabletocometomorrow?
当主语从句出现在感叹句中时,宜用it作形式主语,而把主语从句后置。
Howstrangeitisthatthestudentsaresoquiet!
Whatashameitisthatyoucannotstayfordinner!
连接代词what,whoever,whatever,whichever等引导的主语从句不宜用it作形式主语。
Iswhathetoldusreallytrue?
Whicheverofyouwanttocometoourpartywillbewelcome.
在Itissuggested,ordered,requested,insisted,etc.+that从句中,谓语部分用should+动词原形,should常被省略。(详见第3章虚拟语气)
Itissuggestedthatwe(should)dotheexperimentasecondtime.
在Itisimportant,natural,necessary,etc.+that从句中,谓语部分常用should+动词原形,should常被省略。
Itisimportantandnecessarythatwe(should)keepthebalanceofnature.
在Itisfunny,strange,surprising,apity,ashame,nowonder,etc.+that从句中,有时谓语部分用should+动词原形,来表达说话者的感情色彩,此时should也可省略。
Itisapitythatyou(should)misssuchagoodchance.