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: Cassiopeia:  That 's the fourth power drop . He gets worse with each _ one _ .
Dr.Salik: Prepare to operate .
Cassiopeia: What about the power drops ?
Dr.Salik: Cassiopeia , they 're already killing him . If we just let him lie in that life pod , he does n't hae a chance in a centura . I 'll notify Tigh . I 'll be in ultrasonic scrub .

drop