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 about 28 days, but can last anywhere from 24 to 42 days. There are three major phases of the menstrual cycle: the menstrual phase, the proliferate phase, and the secretory phase. Click here for more information on menstrual products.