Question

a model intrapreneur is art fry, a chemical engineer who in 1974 was working in product development at 3m during the week and singing in his church choir on sundays. he was accustomed to marking the pages in his hymnal with scraps of paper, so that he could quickly locate the songs during the two services at which he sang. the procedure worked fine for the first service, but often by the second one some of the loose scraps of paper had fallen out of their places. fry, not having noticed this, was sometimes at a loss for words.
—the evolution of useful things, henry petroski
what made fry start thinking about an invention?
○ singing in his church choir
○ the failure of bookmarks
○ an article in the sunday paper
○ the success he had locating songs

Explanation:

El texto dice que Art Fry marcaba las páginas de su himnario con trozos de papel para encontrar rápidamente las canciones durante los dos servicios. Pero a menudo, para el segundo servicio, algunos trozos de papel se caían. Esto significa que los marcadores (bookmarks) no funcionaban bien (fallure of bookmarks).

Answer:

the failure of bookmarks