Which of the questions that were posed in Part I are answered in Part 3. How do these answers define Kathy and Tommy´s future?

I'm not sure what you are asking here. Can you clarify what questions were posed in Part I?

This section covers the end of Part One and the beginning of Part Two. In Kathy’s final years at Hailsham, secrets begin to assume an ever more important role in the students’ lives; in their conversations, the substance of the exchange is often in what lies unsaid. A prime example of this is Kathy’s exchange with Tommy; she implies that she cares deeply about him and he suggests that he is unsure whether to pursue a romance with Kathy or with Ruth.

The characters’ new appreciation of subtlety helps to explain why the conversation at the end of Chapter 10 is so shocking. This is not the first time Kathy has confronted Ruth about her disingenuous behavior; the discussion is very similar to the pencil-case incident from the previous section.

In this case, though, Kathy does not let the matter go when she sees Ruth is uncomfortable, and the girls openly discuss matters that are usually not spoken about––for example, the difficulty of adjusting to life at the Cottages and Kathy’s affairs with the veterans. As we learn in Chapter 11, this discussion is itself in violation of the unspoken rule “that anything we told each other during these [bedtime heart-to-hearts] would be treated with careful respect ... we wouldn’t use against each other anything we’d talked about” (126).

This section displays Kathy’s pragmatic regulation of her emotions. She decides early on that she will lose her virginity to someone she does not care much about, so that she will have experience when she falls in love. Likewise, she cares deeply about Tommy but does not allow herself to think of him as a romantic possibility until Cynthia and Hannah suggest that he likes her. This personality trait helps to explain her emotional reserve later in the book when Tommy makes his final donation.

However, we might also view Kathy’s pragmatism as an intellectual posture towards death, to be contrasted with Miss Lucy’s outlook. Miss Lucy chooses to be fully aware of death and its consequences, as she believes this is the only way a person can live a “decent life.” However, this brutal honesty costs Miss Lucy her job and more importantly, her emotional health; she often seems upset and barely able to control herself. Although Kathy’s worldview requires her to avoid thinking too carefully about the donations, it also allows her to experience some happiness and inner peace in spite of her bleak future.