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.
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Question: CO CDR Tom Chandler:  Only one thing I hate more than seeing a submarine on sonar .
XO Mike Slattery: What 's that ?
CO CDR Tom Chandler: * Not * seeing _ one _ .

Answer: submarine


Question: Felix DeMarco:  Okay , I want two cameras ! I know it sounds risky , but we 're gon na do _ two _ !

Answer: cameras


Question: Paul:  In a town like London alone it is reported that the rat population is almost _ one _ billion , but who can really tell ? A proper census would be rather difficult to conduct .

Answer:
population