The refugee crisis(难民危机) in Europe, if ________ properly, can lead to serious social problems.
He is a man of few words, and seldom speaks until _______ to.
Though I have often heard this song _______. I have never heard you _______ it.
“Why was a special meeting called?” “______ a new chairman.”
Finding her car stolen, _______.
A cook will be immediately fired if he is found _______ in the kitchen.