Answer:
During ice ages, the most characteristic change to the planet has been the formation and spread large ice sheets and glaciers across much the Northern Hemisphere.
The Kuiper belt is home to three officially recognized dwarf planets: Pluto, Haumea, and Makemake. Some of the Solar System's moons, such as Neptune's Triton and Saturn's Phoebe, are also thought to have originated in the region.
Answer:
A Type of Drink
Explanation:
A controlled variable remains constant throughout the experiment.
In such experiment, you'd test the volume of one single caffeinated drink. You'd have to use the same type of drink every trial.
They are different by a phase shift of pi/2