11. ________ no need for us to discuss the problem again. It has already been settled.
We ________ such great achievements without your efforts. Thanks a lot.
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 Gamesa 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.