He made _____ experiments to prove his theory, and the number _____ added up to 600.
___________lessons were not difficult.
It’s time _____ lunch.—OK. Let’s _____.
tin Luther King, Jr. put it, peace is not merely a distant goal that we seek, but a means ________ we arrive at that goal.
Once you have become ______to cigarette smoking oralcohol, it is hard to _______it even though you try hard.