I would not be happy with this answer if I were your teacher. I have a couple of problems with it.
First, this part of your answer
technology develops cumulatively, rather than in isolated heroic acts, and that it finds most of its uses after it has been invented, rather than being invented to meet a need.
is directly copied from the book and I do not think that copying from the book constitutes a good answer. (You also don't indicate that this is a direct quote.) Your teacher may, of course, feel differently.
Second, these same lines do not really answer the question. The lines you quote say how technology develops, but they do not tell us what conditions lead to the development of technology.
To answer this question properly, I think you should look to page 260 and beyond in the paperback version. These are the last 4 or 5 pages of the chapter. There, Diamond gives conditions that are needed for technology to develop. Basically, he links technological development to food production. He says that food production led to technology by allowing for sedentary living and by allowing for the existence of specialists who could live off others' work and concentrate on doing things like creating technology.
So, I would talk about food production as the condition that is necessary for the development of technology.