The chairman thought ________ necessary to invite Professor Smith to speak at the meeting.
I wondered what difficulty he had __________ the plan?
Whoever leaves the office last must make sure the light is __________.
-Can I help you? -I'd like a ticket for tonight's show. How much do you __________?
It is generally considered unwise to give children __________ they want.
Driving speed is __________50 kph within the city's __________.