自2010年至今的四级考试中， 共出现过 次
自2010年至今的六级考试中， 共出现过 次
N-COUNT (报纸、杂志的)发行量，销售量 The circulation of a newspaper or magazine is the number of copies that are sold each time it is produced.
The Daily News once had the highest circulation of any daily in the country...
The paper has proved unable to maintain its circulation figures.
N-UNCOUNT 血液循环 Your circulation is the movement of blood through your body.
Anyone with heart, lung or circulation problems should seek medical advice before flying.
...cold spots in the fingers caused by poor circulation.
PHRASE (货币等)流通/不流通/退出流通 If something such as money is in circulation, it is being used by the public. If something is out of circulation or has been withdrawn from circulation, it is no longer available for use by the public.
The supply of money in circulation was drastically reduced overnight.
...a society like America, with perhaps 180 million guns in circulation.
PHRASE (一段时间)不出现在公共场合，不参加社交活动;坐牢;服刑 If someone is out of circulation, they do not appear in public or at social gatherings for a period of time. You can also say that someone is out of circulation when they are in prison.
Political trials were being used to keep prominent activists out of circulation...
I had been out of circulation for a month and knew that many friends would be there.