.He worked day and night, and therefore he _______ buy the sports car.
—Hi, Tom! Could you spare me a minute? I want to have a word with you.—Sure, Jean ____.
--Peter, hurry up! You ______ on the phone.--Oh, I ______. Thank you.
It is a good plan in theory, but it _____ to be seen whether it works in practice.
What do you think of the reason _____ he gave at the meeting yesterday?
Scientists say it may be five or six years ____ it is possible to test this medicine on human patients.