What characteristic of visible light does not depend on the lights wavelength? A. Changing perceived wave frequency for the listener b. Changing perceived amplitude for the listener c. Different whistled on the train d. Changing the speed of the train

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what have scientists found to be the most efficient and effective way to insert new sequences into an individual? a-scientists have created genetically altered foods that release dna during digestion. b-scientists use viruses to insert specific gene sequences. c-scientists irradiate genes so that they can be absorbed through the skin.

answer; i believe the correct answer to the above question is ( friction)