0First, it's "What 01i 01b 00are02b 02i 00 domestic faultlines"02br 02br 00Difficult to tell based purely on that sentence, although I think it might relate to the earth's crustal plates - when they move and overlap it causes earthquakes. The point where the plates overlap is known as a 'fault'. Faultlines are therefore the positioning of the fault and direction it runs in.
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