useless trivia: What Word Means: A Wheat Disease?

Questions

During the American revolutionary war, what country declared war on Great Britain to help the colonies?

During WW I, it was at this city & battle where the Germans introduced mustard gas.?

During WW I, what day of the week was the recommended meatless day?

Dutch-born Swiss scientist, who discovered basic principles of fluid behavior?

Each body cell contains how many chromosomes?