Given scientific fact as input, generate the question from this fact such that it can be answered from the input.

Blood is made up of red blood cells, white blood cells, platelets, and plasma.
Blood is made up of red blood cells, white blood cells, platelets, and what else?

The seven unique crystal types are defined by faces parts of themselves (parts that intersect at various angles).
The seven unique crystal types are defined by what parts of themselves (parts that intersect at various angles)?

An object attached to a spring sliding on a frictionless surface is an uncomplicated type of simple harmonic oscillator.

An object attached to a spring sliding on a frictionless surface is an uncomplicated type of what device?