Sleeping
for example: I was sleeping
Your answer would be “The most memorable trip was when my brother and I encountered a bear.”
It might be said that Anaya´s memoir is a celebration of the "elder". That is why, it is more appropriated to use the term "grandfather(s)" in plural, to make reference to all of them and not just his. It includes older generations and future generations. His father is just an example to illustrate what he is talking about.
What time is the best time for me tomorrow for me a little better today to see if my baby is going with her