He is only too ready to help others, seldom, ____, refusing them when they turn to him.

Never before _____so highly successful in his attempts to change the weather slightly on a very small scale. [ ]

The man got to New York in 1998,_______ some time later, he became a famous computer engineer.

Where’s that report?—I brought it to you __________ you were in Mr. Black’s office yesterday.

The country has already sent up 3 unmanned spacecraft, the most recent at the end of last March.