The milk in the coffee makes the coffee change color and it breaks down the acids in the coffee.
Vertical. Many rocks in mountainous areas can be vertical or even overturned.
<span>An eon is a geologically around tens of millions of years. A period is a million year included in an eon which is also made up of several eras. Therefore my answer is a period due to it being a subset of an era which is a subset of an eon.</span>
