Question: What are the caves with a depth of at least 3.1km ?
Answers:
answer_text: Krubera-Voronja Cave
answer_text: Sarma cave
answer_text: Gouffre Mirolda
answer_text: Gouffre Jean-Bernard
answer_text: Chevé Cave
answer_text: Čehi 2
answer_text: Boybuloq
answer_text: Siebenhengste-Hohgant-Höhle
answer_text: Gouffre Berger