ACCORDING TO THE AUTHOR, THE IMPRACTICABILITY OF USING COAL, OIL SH...

5. According to the author, the impracticability of using coal, oil shale and coal tars as source of energy is

due to______.

A. their being time consuming B. their being money consuming

C. the scarcity of sources D. the lack of technology

IV. Writing

A. Rewrite these sentences