The main idea is about Dolphins. The 2 key details are how they take care of there babies and about their teeth.
<span> The mood is the atmosphere, or total feeling, within a literary work</span>
She has some regrets about not spending more time with her grandfather.
I believe this is the answer because she talks about how their was a slight language barrier and she was preoccupied with life but now that he is gone she wishes she could know more about him.