in the second paragraph the phrase"synthetic fuels" could best be replaced by which of the following? a. biological fuels b. low burning fuels c. fast burning fuels d. artificially made fuelswhich of the following is not mentioned in the passage as an alternative of energy? a. burning of garbage b. geothermal power c. synthetic fuels d. electricityaccording to the author the impracticability of using coal oil shale and coal tars as sources 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
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