In order to support the big family, he worked so hard that ________he made himself ill.
The first use of atomic weapons was in 1945, and their power __________ increased enormously eversince.
I__________ letters this morning and I__________ for four hours so far.
They __________ on the program for almost one week before I joined them, and now we __________ it as no good results have come out so far.
—Hi, Tracy, you look tired.—I am tired. I__________ the living room all day.
I think we can safely __________ that interest rates will go up again soon.