Lawrence Craven,a doctor from the USA,is the author of several published reports,one of ________introduced the idea in 1953 aspirin could reduce the risk of heart attacks.
She raised her finger to her lips as _____ for silence.
—Didn’t the guard see him breaking into the bank? —No, he _______ in the other direction.
We already have ______ pencils, but we need two ______ pens.
“I suppose you _____ that report yet?” “I finished it yesterday, as a matter of fact.”
By all _______, you must try every _______ to help him.