I soon found that the work I was doing had already been done by someone else. _______, I was wasting my time.
If you _____ the medicine you _____ better now.
Gone forever ____ when we used foreign oil.
As she _____ the newspaper, Granny _____ asleep.
I ______, but I was prevent by the heavy rain.
It was not until then that I came to know knowledge ____ only from practice.