Answer:
What is the text of the letter???
Explanation:
3D printing uses computer-aided design (CAD) to create three-dimensional objects through a layering method. Sometimes referred to as additive manufacturing, 3D printing involves layering materials, like plastics, composites or bio-materials to create objects that range in shape, size, rigidity and color.
John Rockefeller moved 60%of all oil till he build his pipe line that cause the railroad to collapse