Fill in each numbered blank with one suitable word or phrase Coal (1) . . . . . . . . . very widely as a source of energy until the last century. With the coming of the industrial revolution, it was soon realized that production would double if coal was used instead of wood. Nowadays, many of the huge factories and electricity generating stations (2). . . . . . . . . . to function if there was no coal In the last twenty or thirty years, however, the use of coal has declined. As a result, there have been changes in the coal industry. It (3) . . . . . . . . . . . . that more people (4) . . . . . . . . . . . . coal if oil and gas were not so readily available. There is more than enough coal in the world for man's needs for the next. two hundred years if our use of coal (5) . . . . . . . . . . . . . Unfortunately, however, about half of the world's coal may never be used. Mining much of it would be very expensive even if it was possible to use new equipment. Question 2.