When you heat something of cool it down you don't change the substance you might change the why is looks, but it is still the same substance. For example you cool water to 0 degrees Celsius it turns into ice but it still is two parts hydrogen and one part oxygen H2O. Physical changes will change state and/or form but it will still be what it originally was on the molecular level. Hope that helped.
It would be A:facing disagreement forces scientist to prove their theories more consistently :)
It would be d all of the above
Answer:
pitched sound
Explanation:
The shrillness of sound is known as Pitched Sound
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