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: The Joker:  There are only two ways to get out of there . _ One _ : I let you out . And two : you jump fifty feet straight up !
Batman: You still intend to free us if we can stay afloat for an hour ?
The Joker: Oh , dear me ! Surely you do n't think I 'd joke about such a serious matter as that , do you ? Time to start filling the tank !
Batman: But ... that 's gas !
The Joker: I do believe you 're right ! But then , who said anything about water ?
Robin: But you ca n't float in gas !
The Joker: No , but you can drown in it !

ways