what is the thesis or topic sentence in "the cub pilot" following the s"t"art strategy?

Read this sentence from the story of my life by helen keller. the most important day i remember in all my life is the one on which my teacher, anne mansfield sullivan, came to me. which element of plot does this sentence best represent?

How does esperanza’s family pass after papas death

During the industrial age, what was one important way businesses told consumers about new products? through phonographs through telephones through telegraphs through catalogues