Simoneit is estimate
的有关信息介绍如下：
这个句子应该这样解释： 它的主语是“that 54 people were killed in the air crash.”,是主语从句,是句子作主语.谓语是“is estimated”.“主语+谓语”是这样的：That 54 people were killed in the air crash is estimated.但是,在英语句子中,这样显得头重脚轻——因为主语太长,谓语太短.于是,就把作主语的That 54 people were killed in the air crash从句移到谓语is estimated后面,前面空出的位置用一个it来替代,称为“形式主语”,所以就变成了“It is estimated that 54 people were killed in the air crash.” 于是,我们的老师们就总结出了类似"It is said/reported/required/known/important/necessary/difficult/hard/vital...that...这种所谓的句型,让广大的同学们来死记硬背. 至于连接词that——不是关系代词,在定语从句中它才叫做关系代词——它在主语从句中不做什么成分,只起一个连接词的作用,这是因为英语中的从句必须要有连接词的,而54 people were killed in the air crash是用的被动语态,不可以再有宾语,意义完整,所以也就不能用别的连接词了,于是就只有用that了. 这样解释是不是更好明白一些.如果觉得我的意见可行就采纳.
