What was the main problem with relying on nature to start a flame? Fire could only be collected with "sticks of wood" that were hard to find.
Fire had to be "carefully guarded," requiring someone to stay behind from hunting.
Fire had to be "carried to the home," which could be dangerous and awkward.
Fire was likely hard to find, requiring a "long journey and a deal of trouble."

It could be 1, 2, or 4, depending on the context.1.) they could have had a fight, and she is too humble to say anything further. she wants robert to say something first.2.) maybe he's staring at a computer playing tetris while she's wearing a *really* tight red dress. just sayin' xd3.) is unlikely given that it's only one sentence worth of context long. 4.) it's possible their relationship is more 'mutual hatred' and they tolerate one another.it could be 1, 2, or 4, as long as you can provide sufficient explanation why. remember this as you write!