_____ the secret of nature, the young scientist has little time for entertainment.
—Did Alan enjoy seeing his old friends yesterday? —Yes, he did. He __________ his old friends for a long time.
The play had already been on for quite some time when we __________ at the New Theatre.
Professor James will give us a lecture on the Western culture, but when and where __________ yet.
—Did you see a man in black pass by just now? —No, sir. I __________ a newspaper.
I __________ there little more than a week when I set to work with the scientist.