Next Sunday is Thanksgiving Day.Have you got any idea _____ we celebrate it?
Since our country has so many good table tennis players, we have to ______ the best ones to take part in the game.
— What has Jack been doing recently?—I don’t know _____ care.
Such a custom came into _______ long ago.
His parents wouldn’t let him marry anyone ______ family was poor.
He attends the evening class ____, that is, Monday, Wednesday and Friday.