the flow of gas or liquid around a closed system
the movement of sth, such as news or money, from place or from person to person
the average number of copies of a newspaper, magazine, etc., that are regularly sold
"by increasing its circulation the newspaper hoped to increase its advertising"
"ocean circulation is an important part of global climate"
"a fan aids air circulation"
I slapped my arms to keep the circulation going.
出自： E. Hemingway