A. the invention of basic machines
B. the discovery of new material
C. new sources power
D. all of the above
Correct Answer: all of the above ✔
Last Updated: July 03, 2019
A. the invention of basic machines
B. the discovery of new material
C. new sources power
D. all of the above
Correct Answer: all of the above ✔
Last Updated: July 03, 2019