I would say the answer is C because it says heat and the passage was talking bout fire, it just seems like the best answer, sorry if I'm wrong :)
Answer:
it might be the first one I'm pretty sure it is.
I feel 'while' would be the connecting word here. Without it the sentence flops and it helps add onto it with the extra sentence part.
I sharpened your pencil. You were away.
'While' should be the conjunction.
Explanation:
number of people or things that are located, gathered, or classed together is called group
To look back in time and remember something that already happened
