When _____ to hand in his homework, Philip told his teacher that he had left it home.
The library's study room is full of students _______ for the exam.
The scientists were waiting to see the problem _______.
The foreigner tried his best, but he still couldn't make his point _______ .
People _______ in the city do not know the pleasure of country life.
The _______ price will save you one dollar for each dozen.