-What do you think of our school, Linda?
-It's a good place for us to ______ ourselves for the future.
A.promise B. prove C. prepare D. present
-Mum, where is Dad?
-He ______ a speech for tomorrow's meeting.
A.was preparing B. is preparing C. has preparing D. will prepare
Julie didn't leave her office ______ the police arrived.
A.However B. whenever C. while D. until