The newly-invented cell-phones emit large amounts of radiation. This is why they ________ disapproval from experts as soon as they are on sale.

ProfessorWilliams keeps telling his students that the future tothe well-educated

only too ready to help others, seldom, ______,refusing them when they turn to him.

Many people believe that ______ will take years to develop a car that does not pollute the air. [ ]

Swimming is __________ diving.