"Since the blackout, everything seemed more urgent than ever"(113). Because of this realization, Doon is going to be more determined to figure out the problem and save the city. This realization will help the citizens of the city understand the problem.
"To leave Ember, they must go on the river"(192). I thought Lina and Doon will tell the city that they will journey out, and if they find the city, they will come back. This realization could mean a way to save the citizens.
"They were not in complete darkness... 'It's the lights of the city' " (252). This was the moment when they could finally see the city, and Lina and Doon probably had a lot of hope at this moment.
"When it comes time for people to leave this place, is this the way they will come?"(262). This makes me wonder if they really know what was going on years ago. This tells me the people were probably oblivious to what's happening.
"Must we go mile after mile in absolute darkness?"(187). At the time, I wondered if it really was a way out or just a way to a short-term solution. They might have lost some hope at this moment and were thinking about giving up.
"Wouldn't it be strange to have a blue sky?" (136). This is odd because their "sky" is black and shows no light. I wonder if there was light, the city wouldn't be dying. This tells be that Lina has a great imagination and could envision a logical world.