Which sentence belongs to the conclusion of a memoir

What do you think inspires people to come up with great inventions? explain in 4 sentences

The institute of international research is holding its annual convention. this year more than 500 scholars have been invited to hear research reports on many timely topics. approximately 250 big name scientists will be winging their way to washington, d.c. how can the underlined sentence be revised so that it fits the tone of the passage? a) approximately 250 people will be in washington, d.c. b) approximately 250 bigwigs will be flying to washington, d.c. c) approximately 250 science people will be going to washington, d.c. d) approximately 250 well-known scientists will be arriving in washington, d.c.

What is the main idea of this paragraph from the volcanoes section of the ready.gov website