huinventors1-1, Exercise 1: Invention, discovery, theory

Model answer:

Invention: a thing or method that did not exist before and can be patented, such as Rubik's cube or Bíró's ballpoint pen.
Discovery: finding something that already existed, such as Szent-Györgyi isolating vitamin C. It is not an invention in the patent sense, though it can lead to one.
Theory or design: an abstract idea, such as von Neumann's computer architecture, which is not a physical object.

Keeping them apart avoids claiming that a nation "invented" something that was a discovery or an idea. Details should be checked.