(Question)
Q: Dutch scientist christiaan huygens' principle of what states that every point on a wavefront is a source of wavelets that spread out in the forward direction at the speed of the wave itself? Choices: - electromagnetic dynamics - energy propagation - wave dynamics - wave propagation A:
(Answer)
wave propagation

(Question)
Q: Stis are diseases caused by what that spread through sexual contact? Choices: - amoeba - ecosystems - parasites - pathogens A:
(Answer)
pathogens

(Question)
Q: Physical properties are characteristics that describe what as it exists? Choices: - imagination - antimatter - life - matter A:
(Answer)
matter