A study ________ in the U.S.A. in 1977 showed that the chemical ASA in aspirin could prevent a stroke. A. carrying out B. carried out C. working out D. worked out
Little ______about his own health though he was very ill.
The light will be thrown ______ the cause of cancer by research that is now in progress.
—Why was he unhappy yesterday? —A letter from home ______ an attack of homesickness.
_____great progress Jim had made in _______ time!
The governor made no ______ about the fight between the Red Shirts and the Thai Troops.