TASK DEFINITION: In this task, we ask you to elaborate the sentence without changing its general meaning. You can do so by explaining further the input sentence, using more precise wording, adding qualifiers and auxiliary information etc.
PROBLEM: During winter the lake water becomes well mixed , and the lake water is less clear because of tannins and calcium carbonate particles .

SOLUTION: During winter , the lake becomes well mixed , and recent research indicates that during this phase of the colour cycle , the lake is somewhat murkier due to the redistribution of tannins and calcium carbonate particles throughout the lake .

PROBLEM: An IATA airport code , is a three-letter code that can be used to identify airports .

SOLUTION: An IATA airport code , also known as an IATA location identifier , IATA station code or simply a location identifier , is a three-letter code designating many airports and metropolitan areas around the world , defined by the International Air Transport Association ( IATA ) .

PROBLEM: The word cipher in French is " cifre " and in Medieval Latin " cifra " , from the Arabic " sifr " , meaning ' zero ' .

SOLUTION:
The word " cipher " ( minority spelling " cypher " ) in former times meant " zero " and had the same origin : Middle French as " " and Medieval Latin as " cifra , " from the Arabic " sifr " = zero ( see Zero Etymology ) .