I ____him to give up smoking, but I failed.
We all thought that Betty could have run _______ if she had worn the sports-shoes that day.
In that traffic accident last night the man who hit five people in a row had drunk so much that he could no longer_______ between fantasy and reality.
Mr. Andrew taught his students how to develop the basic skills in the physics class, ______ everything through jokes and experiments.
Mr. Bryan is a/an _______ secretary in our office, for he is able to do tasks successfully, without wasting time or energy.
There was enough evidence to prove that the explosion in Robinson’s house _______ the leak of natural gas.