Never before _______ so highly successful in his attempts to forecast the weather accurately on a small scale.
—I’m afraid I can’t finish the book within this week. —__________.
The hunter insisted that he _____ a tiger and that a searching team ______ to hunt for it.
You have to keep on learning if you want to keep ______ with the development of modern science and technology.
The athlete fell off his bike when he _____ down the hill.
There is ______ is called Mr. Smith in our workshop.