We should try to prevent air pollution__________.

No sooner _____ a paper on his latest research than he was asked to write another for the program.

Chan is________ to turn up at the party for charity, since he is always enthusiastic about such things

In 1901, H. G Wells, an English writer, wrote a book_______ a trip to the moon. [ ]

He was nearly killed in a car accident the other day.— Oh, when was ________ exactly?— It was on April 28 ________ he was riding a bike on the driveway.[ ]