instruction:
Given a scientific question, generate a correct answer to it.
question:
Any sound with a frequency above the highest audible frequency is defined as what, a phenomenon useful in medical diagnosis and therapy?
answer:
ultrasound

question:
Learning to get used to something after being exposed to it for a while is associated with what kind of learning?
answer:
habituation

question:
What is the source of most of the energy used?
answer:
the sun