I'm sure that someone forgot to lock the door.
Someone must ___________________________________________________________________

You should take the train instead of the bus.
If ______________________________________________________________________________

The package was too heavy for Peter to carry.
The package was so _______________________________________________________________

Jane was absent from class because of her sickness.

Because Jane was _________________________________________________________________

He went to London. He had lived there when he was a boy.
He went to London where ___________________________________________________________

People thought that the cover was made of iron.
The cover________________________________________________________________________

They spent more money, they had to work harder.
The more _______________________________________________________________________

If you do not try hard, you can't pass the examination.
Unless __________________________________________________________________________

I wasn't there yesterday, so I didn't know who he was.
If I _____________________________________________________________________________

They are producing motorbikes in Vietnam.
Motorbikes are ___________________________________________________________________