Time should be made good use of ________our lessons well.
I _______ to help you but I was not able to spare any time.I _______ a paper last night and I'll have to finish it today.
There are so many books! It is not easy for us to decide what to take and what to_______.
When I try to understand _______ that prevents so many Americans from being as happy as one might expect, it seems to me that there are two causes.
The science of medicine, _______ progress has been very rapid lately, is perhaps the most important of all the sciences.
He is _______ to get there in time if he starts right now.