When the man first learnt how to make a fire, he began to use fuel for the first time. The first fuel he used was probably wood. As time passed, man (17) ………… discovered substances such as coal and oil.
Coal was used very widely as a (18) ………… of energy until the end of the 19th century. (19) …………
the coming of the industrial revolution, it was soon realized that production (20) ………… if coal was used
instead of wood. Nowadays, many of the huge factories and electricity generating stations would not be able
to function if there was no coal.
In the last forty or fifty years; (21) …………, the use of coal has declined. As a result, there (22) …………
changes in the coal industry. It is believed that more people would use coal if oil and gas were not readily
available.
17. A. effectively B. locally C. eventually D. rapidly
18. A. form B. source C. supply D. consumer
19. A. As B. For C. With D. From
20. A. would double B. will double C. doubles D. had doubled
21. A. however B. therefore C. as a result D. as well as
22. A. are B. were C. will be D. have been