The old man is too tired _________ go any further.
Many parents find it difficult _______ with their children.
—I don’t think English is as_______ as maths. —I agree with you.
Don’t forget to return the book to me when you finish _______.
Now many of us play sports at ______ least ______ hour a day.
Both players are in hard work, ________ wanted to lose the game.