When man first learned (25)__________ a fire, he began to use fuel for the first time. The first fuel he used was probably wood. As time passed, man eventually discovered that (26)__________ would burn.
Coal was not used very widely as a source of energy until the end of the 19th century. With the coming of (27)__________, 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 would be unable to function if there was no coal.
In the last twenty or thirty years, however, the use of coal has declined. (28)__________, there have been changes in the coal industry. It is believed that (29)__________ if oil and gas were not 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 does not increase. Unfortunately, however, about half of the world’s coal may never be used. (30)__________ would be very expensive even if it was possible to use new equipment.
- A. what to do B. when to work C. how to make D. where to take
- A. substances such as coal and oil B. factors such as coal and oil
C. elements such as coal and oil D. ingredients such as coal and oil
- A. the social innovation B. the technological conservation
C. the economic resolution D. the industrial revolution
- A. In addition B. As a result C. On the other hand D. In other words
- A. more people employ coal B. more people will apply coal
C. more people consumed coal D. more people would use coal
- A. Mining much of it B. Mining much at it C. Mining much to it D. Mining much for it
