noun
[ ,] a level or point that sth reaches that is thought to be important 重要水平；关键点位 ◆ The price of oil has passed the $40-a-barrel mark. 石油价格突破了每桶 40 元的关口。 ◆ Unemployment remains below the four million mark. 失业人数依然维持在 400 万的水平之下。
Mark [] (followed by a number) a particular type or model of a machine or vehicle （後接数字）（机器或车辆的）型号，款式 ◆ the Mark II engine 二型发动机
