We have to______the costs of the new system against the benefits it will bring.
As there was not much chance to find good jobs in their hometown, many young men now tried to __________ their fortune in cities.
His words are strongly impressed __________ my memory.
It is __________ to discuss the question again and again.
__________ it will take me six weeks, I am determined to finish the job.
__________ for one year was a very enjoyable and exciting experience for me.