I don’t doubt _______ he can finish the task, but I doubt _______ he is willing to do it.
—Do you know if he ____ to play football with us? —I think he will come if he _____ free tomorrow.
This place is worth _______.
Not only his parents but also he ____ watching football games on TV.
I don’t know ______ to stay or go.
I don’t know _____ he will come or not tomorrow.