Which is a characteristic of the "invasion novel"?

Which element in the room does the narrator in the yellow wallpaper focus on through much of the story

Which two passages in this excerpt from the death of ivan illych does leo tolstoy use to suggest that ivan ilych feels like his life is slipping away from him? "what's the use? it makes no difference," he said to himself, staring with wide-open eyes into the darkness. "death. yes, death. and none of them knows or wishes to know it, and they have no pity for me. now they are playing." (he heard through the door the distant sound of a song and its accompaniment.) "it's all the same to them, but they will die too! fools! i first, and they later, but it will be the same for them. and now they are merry . . the beasts! " anger choked him and he was agonizingly, unbearably miserable. "it is impossible that all men have been doomed to suffer this awful horror! " he raised himself. "something must be wrong. i must calm myself—must think it all over from the beginning." and he again began thinking. "yes, the beginning of my illness: i knocked my side, but i was still quite well that day and the next. it hurt a little, then rather more. i saw the doctors, then followed despondency and anguish, more doctors, and i drew nearer to the abyss. my strength grew less and i kept coming nearer and nearer, and now i have wasted away and there is no light in my eyes.

Which resource is most useful for finding the correct spelling of words?