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.) travels faster in solids because the particles are closer together.

air is a gas water is a liquid

0.93xc=0.93x3x10^8m/s

2.54cm is 1 inch

360seconds i 1 hr