"The cryosphere: an excellent choice! It's important to remember that 'cryosphere' is a word describing the regions of the Earth covered by frozen water. In case you forget the word's meaning, try thinking of it this way: the first part of the word, 'cryo', comes from the Greek word 'kyro', meaning 'cold', and what happens when water becomes really cold? The water freezes! The second part of the word 'sphere' relates to the Earth, because the Earth's shape resembles a sphere. If you put these ideas together, you'll remember that the cryosphere describes the frozen parts of the world!"