SAVING ENERGY PRACTICE TEST 1I. CHOOSE THE WORD OR PHRASE THAT...

50. - 200 CAU TRAC NGHIEM KQ ANH 9 -BAI 6-7
200 CAU TRAC NGHIEM KQ ANH 9 -BAI 6-7

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

energy is due to ____

a. lack of time.

b. high cost

c. scarcity of sources. d. lack of technology.

HVH - HM