pipeline      
noun [ C ] uk/ˈpaɪp.laɪn/ us/ˈpaɪp.laɪn/
 (常指铺设在地下的)管道,管线
a very long large tube, often underground, through which liquid or gas can flow for long distances
 Idiom   
in the pipelineidiom  在筹划中;在进行中
being planned
  The theatre company has several new productions in the pipeline for next season. 剧团正在为下一个演出季排练几个新剧目。