1、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。
2、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。
3、What caused the accident remains unknown.
事故的起因是未知的。
4、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。
5、Whether we will go for an outing tomorrow remains unknown.
我们明天是否会去郊游仍旧未知。