Question

I can't get this wrong. These parts are made from pieces that are exactly the same:

A.interchangeable parts
B.steam Engines
C.mass production
D.railroad ties

Answer 1

I gonna have to go with A. There's hundreds of different types of steam engines and mass production is simply the mass production and a good and railroad ties...it just didn't make sence to me because there are many different materials you can use that will serve as a railroad tie.