Answer:
"not useful"
Explanation:
The prefix im expresses negation; not, so when you call something impractical you are saying no-practical or not useful
2 he hasn’t arrived,but he said he’d be here soon.
False???
STEP BY STEP EXPLANATION:
The revision that would help expand the ideas in the excerpt is <span>adding more specifics about the sailors' beliefs about the island.
</span>The author just mentions their beliefs briefly, but doesn't really expand on that topic, which may be relevant further down in the text. This is why I believe that adding such details is important to include in this essay to make it more detailed and easy to understand.