At the Copenhagen conference, all the countries were called on to do all they could to control greenhouse gas emissions ______ it was too late.
. The police refused to _____ the clues they were working on.
. Driving a car without insurance can have _____ consequences.
. Probability is the mathematical study of the _____ of an event's occurrence.
. New mineral resources may be discovered during the forthcoming Antarctic _____.
They have been waiting for many hours to see the singer, but the airplane must have been _____.