The Band Test. The back and front of your bra band should be level and parallel to the floor when you look at yourself from the side in a mirror. If the band is too tight, digs into your flesh or is just plain uncomfortable, it's too small.
Scanning electron micrograph of a phagocyte (yellow: neutrophil) engulfing some bacteria (orange: anthrax bacilli). Phagocytes are the white blood cells that protect the body by eating (phagocytosing) dirt, bacteria and dead or dying cells. They are important for fighting infections.
Monocytes share the vacuum cleaner (phagocytosis) function of neutrophils, but are much longer lived as they have an additional role: they present pieces of pathogens to T cells so that the pathogens may be recognized again and killed, or so that an antibody response may be mounted.