What material from real life does Zusak draw from in creating his stories for The Book Thief?

Which word best describes the author's tone in this excerpt from "that spot" by jack london? i don’t think much of stephen mackaye any more, though i used to swear by him. i know that in those days i loved him more than my own brother. if ever i meet stephen mackaye again, i shall not be responsible for my actions. it passes beyond me that a man with whom i shared food and blanket, and with whom i mushed over the chilcoot trail, should turn out the way he did. i always sized steve up as a square man, a kindly comrade, without an iota of anything vindictive or malicious in his nature. i shall never trust my judgment in men again. why, i nursed that man through typhoid fever; we starved together on the headwaters of the stewart; and he saved my life on the little salmon. and now, after the years we were together, all i can say of stephen mackaye is that he is the meanest man i ever knew. a. excited b. ironic c. indignant d. playful

In a series of experiments, hershey and chase radioactively labeled dna and protein in viruses and then used labeled viruses to infect bacteria. hershey and chase's experiments definitively showed that a. dna and not protein is the genetic material. b. dna and protein work together as a cell's genetic material. c. protein and not dna is the genetic material. d. neither dna nor protein act as a cell's genetic material

Today’s readers have more scientific knowledge than readers of previous eras what effect does that have on their reading of science fiction stories