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.
Regular and irregular periods. In regular menstruation, a woman's cycle follows a predictable pattern. A menstrual cycle lasts around 28 days, but it can vary from 24 days to 35 days, depending on the individual. Most women have between 11 and 13 menstrual periods each year.