淡定的机车
1、That he finished writing the composition in such a short time surprised us all.
他在如此短的时间内写完作文使我们十分惊讶。
2、Whether we will go for an outing tomorrow remains unknown.
我们明天是否会去郊游仍旧未知。
3、Who will be our monitor hasn't been decided yet.
现在还没有决定谁会成为我们的班长。
4、Whom we must study for is a question of great importance.
“我们为谁而学习”是个很重要的问题。
5、What caused the accident remains unknown.
事故的起因是未知的。
扩展资料：
用it 作形式主语的结构
(1) It is +名词+that从句
It is a fact that … 事实是……
It is an honor that …非常荣幸
It is common knowledge that …是常识
(2) it is +形容词+that从句
It is natural that… 很自然……
It is strange that… 奇怪的是……
(3) it +不及物动词+that从句
It seems that… 似乎……
It happened that… 碰巧……
(4) it is+过去分词+that从句
It is reported that… 据报道……
It has been proved that… 已证实……
参考资料来源：百度百科-主语从句
阿富汗小海参
主语从句的时态不受主句时态的影响和限制（1）That he finished writing the composition in such a short time surprised us all.（2）Whether we will go for an outing tomorrow remains unknown.（3）Who will be our monitor hasn't been decided yet.（4）Whom we must study for is a question of great importance.（5）What caused the accident remains unknown.（6）Whatever you did is right.（7）Who the watch belongs to is unknown.（8）What we need is time.（9）What we need are good doctors.
我们家懒格格
主语从句，即在复合句中充当主语成分的句子。
That he finished writing the composition in such a short time surprised us.
他在很短的时间内写完作文让我们很惊讶。
主语：he finished writing the composition in such a short time
谓语：surprised
宾语：us
主语从句是在复合句中充当主语的从句，通常放在主句谓语动词之前或由形式主语it代替，而本身放在句子末尾。
It作形式主语和it引导强调句的比较
主语从句常用it作形式主语，一般常用句型为：It is+{名词/形容词/过去分词}+主语从句例如：
It is still a question whether she will come or not.
It is strange that you should like him.
It is still unknown which team will win the match.
以上内容参考：百度百科-主语从句
优质英语培训问答知识库
