— Can you come to my birthday party tonight? — I’d love to, but I______ on a patient at 6 o’clock.
When he was a boy, he used to go there and watch _____.
When do you think ______ start the new attack?
During the tourist season, there are many people wandering in this city to see the old castles _____ in the sixteenth century.
_______ which way to take, the little boy behaved like a real gentleman who comforted his sister from time to time.
He doesn't know what to say, for it is the first time that he ______ with a girl.