Question

fix the one word that is used incorrectly.
californias climatic conditions are like the mediterraneans: dry in summer, wet and mild in winter. in fact, more then half of the states yearly precipitation falls between december and february.

Explanation:

The word "then" is an adverb used to refer to time or sequence, but here we need a comparative term to pair with "more". The correct word for this context is "than", which is used in comparisons.

Answer:

Replace "then" with "than". The corrected sentence is: "In fact, more than half of the state's yearly precipitation falls between December and February."