What does the phrase "closed system' mean as it relates to the cardiovascular system?  

Ori works at a flower shop in her town. when customers come in to purchase flowers as gifts, lori takes the time to really listen to their needs so she can recommend the perfect bouquet to them. as a result, lori's customers leave happy and return to this shop whenever they need to give a gift. lori's co-workers like her because she gets along with everyone and compliments them on the bouquets they have put together. what workplace habit does lori demonstrate?