Final answer:
The excerpt from paragraphs 5-6 that would be the most useful in an informational paragraph about the word condolences is: 'And on behalf of the American people, I thank the many world leaders who have called to offer their condolences and assistance.'
Step-by-step explanation:
The most useful excerpt from paragraphs 5-6 for an informational paragraph about the word condolences is:
"And on behalf of the American people, I thank the many world leaders who have called to offer their condolences and assistance."
This excerpt shows that condolences are expressions of sympathy and support that world leaders offer to the American people in times of tragedy.