单词：progressions
音标：[prəˈgreʃənz] ；
n. （事件的）连续( progression的复数形式 ); 一系列; <数>级数; 发展
n. a series with a definite pattern of advance
n. a movement forward
n. the act of moving forward (as toward a goal)
n. a movement forward
n. the act of moving forward (as toward a goal)