The elderly _________ good care of in public places like supermarkets and airports; they are likely to get lost.
The theory he sticks to ______ to be of no use in our studies.
The life he is now used _____ quite different from ours.
He has changed a lot. He _______ not what he _______.
“When did he leave the classroom?” “He left _______ you turned back to write on the blackboard.”
“Shall Mary come and play computer games?” “No, _______ she has finished her homework.”