(A)3D printing is surely one of the biggest technology developments of recent times. It is the method of creating almost any object layer by layer. Objects created by 3D printing include cars, clothing, food, and even body parts. Here’s how the process works.   The first step is to make a file of a 3D model on a computer. This is the guide for the printer, telling it what materials go where, and how to build the finished product from scratch. Next, the materials are loaded into the printer. The machine follows the instructions that have been programmed into it, starting with the bottom layer and adding more material on top of that in a 3D structure until the product is completed. Each layer is blended with the ones above and below it so that there is almost no visible way to tell layers apart.   One leading company in terms of 3D organs and body parts in Organovo. They have successfully created liver tissues, which is needed in hospitals. Now, the company is teaming up with a skincare company called L’Oreal to develop 3D-printed skin. This could be used to help patients recover from burns and other wounds. Another advantage is that it is also a way of creating something on which to try out L’Orealnew products, which puts an end to animal testing.
【題組】70. What is said about 3D printing?
(A) It can only create objects with plastic materials.
(B) Materials are pieced together layer by layer during the process.
(C) The technology is much older than people think.
(D) It is expected to enable humans to go to the moon in the future.