If a physical change has taken place, which of these is most likely true? a permanent change has taken place. the changed substance retains its unique properties. atoms rearrange to form a new substance. the molecular composition of a substance changes.

A physical change means that none of the atoms or chemical bonds have been changed inside of something. Therefore, if you make a physical change, you should be able to revert it back. That means that the answer to this question is "The changed substance retains its unique properties." because it is the only answer choice where nothing major is being changed. The rest of the answer choices indicate that once changed, it isn't able to be changed back.

The owl pellet must be ejected before the owl can eat again.

Explanation: When the pellet moves from the gizzard back up to the proventriculus to be regurgitated it blocks the owl's digestive system which stops them from eating new prey until the pellet is ejected from their body.