I would say B because a surplus of food means that there is a lot of food to go around, meaning that people wouldn't have to worry about finding food all the time. So, they could go specialize in other jobs and skills, leading away from a food-centered civilization
Because B.C stands for Before Christ and A.D means the year of our lord so historians took a turn from the traditional christian time method and made it B.C.E (before common era) and C.E (common Era)
marble i think since they build a few temples for the gods with marble but normal people would build with mud idk if it can be called cement.
Because Mae Jemison became the first African American woman to travel in space
