The textbooks ________ for teaching English as a foreign language came out in the 16th century.
Little Tom hid himself in the place_______ couldn’t be found, _______make her mother annoyed.
The river______ surface used to be covered with waste and rubbish is now taking on a new look.
We have a slight problem with the temperature control but_______ everything’s fine.
They got two free tickets to Canada, otherwise they______ able to afford to go.
Has the Channel Tunnel improved the _______of goods between the British Isles and mainland Europe?