— When can I see you, Mr Black? Three o’clock this afternoon?— Oh, no. I ________ a meeting then. 

Do you know when Mr Brown_______ ?  When he_______ , please let me know.

She ought to stop working; she has a headache because she ________ too long.

－When shall we set off?－We ____ start off at five o’clock if it ___ raining by then. 

--Our English teacher is back home from Britain now.--Yes, she _____there for just three months.