Definition: In this task, you will use your knowledge about language (and common sense) to determine what element the marked number refers to. The numbers are marked with two underlines around them, like: _ number _. Your answer should be chosen from the given text, and should not contain other words.
Input: Angela Montenegro:  So we would get time of death wrong . But wait . Would n't everyone at the Body Farm know how to use that ?
Dr. Camille Saroyan: Yes , but from what Booth said only one of them had an alibi for what we thought was time of death . I 'm guessing because he knew he 'd need _ one _ .

alibi