what role do variations have in the theory of evolution by natural selection? i need answer fast pls i will give brainliest to first real answer

Kelly ran electricity though a sample of water using electrolysis. the water changed into two gases, x and y. it was not possible to break down the gases x and y into simpler particles.

What are genotypes? what are phenotypes?

Acar company is testing seatbelts using crash test dummies. the company finds that when cars come to a sudden stop, the crash test dummies' bodies continue to move forward. the seat belt keeps the crash test dummies from hitting the back of the seat in front of them. why do the crash test dummies' bodies continue to move forward even though the car stopped? a. the friction opposing their bodies' movement keeps them in motion. b. the inertia of their bodies keeps them in motion. c. the forward acceleration of the car keeps them in motion. d. the gravity pulling on the car keeps them in motion.