Which of the following statements are true?
A Simple machines use electricty
B Simple machines are made from only one part
C Compound machines are made from two or more simple machines
D Compound machines make the job harder

C-) Compound machines are made from two or more simple machines

Explanation:

Simple machines use the principle of Lever, where a force multiplied by a distance is used. That is why a simple machine does not produce electricity. Simple machines must be composed of at least two parts. For this reason the combination of simple machines results in a compound machine.

a) electrical > light, sound, and thermal< < < <

) the mechanical energy of the firefighter moving.< < < < a) electrical > light, sound, and thermal< < < <

c) both a and b.