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 Doctor:  Welcome !
Billy Shipton: Where am I ?
The Doctor: 1969 . Not as bad as it goes . You 've got the moon landing to look forward to .
Martha Jones: Oh , the moon landing 's brilliant . We went 4 times Back when we still had transport .
The Doctor: Working on it !
Billy Shipton: How did I get here ?
The Doctor: Same way we did . Touch of an angel . Probably the same _ one _ since you ended up in the same year . No , no , no , do n't get up . Time travel without a capsule . Nasty . Catch your breath , do n't go swimming for 30 minutes .
Billy Shipton: I do n't . I ca n't .
The Doctor: Fascinating race , the Weeping Angels . The only psychopaths in the universe to kill you nicely . No mess , no fuss . They just zap you into the past and let you live to death . You die in the past , and in the present , they consume the energy of the life you might have had . They 're creatures of the abstract , they live off potential energy .
Billy Shipton: What in God 's name are you talking about ?
Martha Jones: Trust me , just nod when he stops for breath .
The Doctor: Tracked you down with this . This is my timey , wimey detector . Also , it can boil an egg from 30 paces away . Whether you want it to or not , actually . I 've learned to stay away from hens . It 's not pretty when they blow .

angel