249. A_____ has taught us what atoms are made up of and how powerful the atom bomb is.
My neigh bours used to give me a hand in time of trouble, _______ was very kind of them.
I want to use the same tools _______used in your factory a few days ago.
I have two grammars, ______are of great use.
That is not the way ______I do it.
He is working hard, ______will make him pass the final exam.