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.

Positive Example 1 -
Input: The Inheritance Cycle is a series of fantasy books written by Christopher Paolini.
Output: The Inheritance Cycle is a tetralogy of young adult high fantasy novels written by American author Christopher Paolini.

Positive Example 2 -
Input: The Greco-Roman or Graeco-Roman world , refers to geographical regions and countries who had the language , culture , government or religion of the ancient Greeks and Romans.
Output: The Greco-Roman world , Greco-Roman culture , or the term Greco-Roman (spelled Graeco-Roman in the United Kingdom and the Commonwealth), when used as an adjective , as understood by modern scholars and writers , refers to those geographical regions and countries that culturally ( and so historically ) were directly , long-term , and intimately influenced by the language , culture , government and religion of the ancient Greeks and Romans.

Negative Example 1 -
Input: Boryla, an American football quarterback, did not participate in the 1952 playoffs.
Output: Boryla was not in the 1952 playoffs.

Negative Example 2 -
Input: The wild population in China decreased to around 2,000 in 2005.
Output: By 2005, the wild population decreased to about 2,000.

Now complete the following example -
Input: The exact cause of bipolar disorder is unknown .
Output: 


Output: The causes of bipolar disorder likely vary between individuals and the exact mechanism underlying the disorder remains unclear .