In the case of the B (or center) pillar on four-door sedans, the pillar is typically a closed steel structure welded at the bottom to the car's rocker panel and floorpan, as well as on the top to the roof rail or panel.
On an average a period lasts between 3 to 5 days. It is normal for a girl to have irregular periods in the beginning. During this time, the duration of her periods may vary from as short as 2 days to as long as 7 days. It can take up to a year for periods to become regular.
The average menstrual cycle lasts 28 days (counting from the first day of bleeding to the first day of the next cycle). For some women, though, cycles can be as short as 21 days. For others, they can be as long as 35 days. A normal period lasts between two and seven days.