—Tom has played a lot of computer games recently.—Yes, that might ________ his failure in the midterm examinations.
A study ________ in the USA in 1977 showed that the chemical ASA in aspirin could prevent a stroke.
It’s obvious that the Beijing Olympic Games a great success. A.kept B.showed C proved D.remained
Scientists ____ thousands of chemicals before they decided on the right one in the end.
The deserted island is only _______ by boat.
As is widely acknowledged, a great number of traffic accidents ____ numerous deaths and countless property loss all over the world every year.