Do you know the stages every inventor must ________ before they can have their invention________ .
Is it John that is being scolded in the manager’s office? No. It ______ be him. I saw him on the way just now.
The question came up at the meeting_____ we had enough money for our research.
Twenty of the students will have sports, the rest ___ studying here
He is a strict but kind-hearted father, ____ the children respect but are afraid of.
She ______ behind the door in order not to be found. Two minutes later she was safe again.