There exist three ways which are chronological-flashback-patching in terms of narrative time, and two structural forms, interior and exterior, in terms of narrative space.
在叙事时间上，有顺———倒———补三种形态。在叙事空间上，有内部与外部两种结构形式。
Two structural forms can change under pressure to realize a water supply and drainage function of automatic quantify for a single opening.
两种结构形式均可依靠压力的变化，实现单口自动定量给排水功能。
Two structural forms can change under pressure to realize a water supply and drainage function of automatic quantify for a single opening.
两种结构形式均可依靠压力的变化，实现单口自动定量给排水功能。
应用推荐