Not until they left school________how much their teachers loved them and helped them.
Mr. Green asked Lily ________ she had written to her father _______.
Anne felt nervous ____ she gave a speech in front of so many students.
---- Do you know our town at all?-----No, this ________ the first time I _________ here.
Last Sunday, they arrived at the farm _____ they had never paid a visit before.
When______ a new word, you’d better_______ a dictionary.