My friend sent me that i dont know what it means tho

The internal combustion engine was an innovation of

Both the nervous and endocrine systems send electrical and chemical signals for internal communication. select the best answer from the choices provided t f

Which of these innovations led to increased production in american factories in the early 1800s? a. the use of interchangeable parts b. the construction of canals c. the invention of the mechanical reaper d. the availability of electricity