Answer:
1. Senko is most concerned with saving endangered sea turtles
2. He focuses his research and life's work on marine resource sustainability.
Explanation:
1. The central idea here in this passage is that "Senko is most concerned with saving endangered sea turtles."
This is because that what the whole passage is about. It talks about Senko's interest in saving turtles due to his memorable encounter with a turtle while he was younger.
2. The sentence from the text that best shows the development of the central idea in Part A is "He focuses his research and life's work on marine resource sustainability."
This is because, given that Senko's focus is his research and life works on marine resources sustainability, it best shows the development towards his most concerns which is about saving the endangered turtle
