Simple tools made from simple machines were developed and invented by people thousands of years ago in order to:

a. Make their life easier
b. Help them do their work.
c. Have more effective transfer of their energy.
d. All of the above.

Question

Simple tools made from simple machines were developed and invented by people thousands of years ago in order to:   

a. Make their life easier
b. Help them do their work.
c. Have more effective transfer of their energy.
d. All of the above.

anonymous · Answer

I think D

thesmartone · Answer

Why do you think D? Also no direct answers please @kaylanicole1797 Also read the CoC: http://openstudy.com/code-of-conduct Thanks