A. This type of drone is very popular nowadays. It is a small remote-controlled* aircraft that looks like a helicopter, with four blades on the top. It can be used specifically to film or photograph things from the air. B. This machine can make almost anything. First of all, you make a computer model of the thing you want to create. Then you need to choose a material for the object. The most popular material is plastic. After that, you start the process, and the device starts working, creating the thing layer by layer**.