interference,diffraction

A wave should consist of four properties:

1) reflection
2) refraction
3) diffraction
4) interference

Something consist of the properties of reflection or refraction ONLY can not be considered as a wave.

Example:

A ball reflect when it hit another object, like ground, wall.
A trolley refract by changing it's direction of travel when enter a grass field from a smooth road.

But they are not wave.

So further test for interference and diffraction is needed.