Teacher: 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.
Teacher: Now, understand the problem? If you are still confused, see the following example:
The Inheritance Cycle is a series of fantasy books written by Christopher Paolini.
Solution: The Inheritance Cycle is a tetralogy of young adult high fantasy novels written by American author Christopher Paolini.
Reason: The output sentence elaborates on the input sentence without changing its general meaning e.g. "tetralogy of young adult high fantasy novels".

Now, solve this instance: The 1950s was the decade that started on January 1 , 1950 , and ended on December 31 , 1959 .
Student:
The 1950s ( pronounced " nineteen-fifties " ; commonly abbreviated as the fifties ( among other variants ) ) was a decade of the Gregorian calendar that began on January 1 , 1950 , and ended on December 31 , 1959 .