动词是deepen，例如：
1、Asking juicy questions appears to be a transferable skill for deepening collaborative inquiry into the science content found in exhibits.提出有趣的问题似乎是一种可以转移的技能，能够深化针对展品中发现的科学内容的协作性研究。
2、There were plans to deepen a stretch of the river.曾经有过加深一段河道的计划。
3、The gloom deepened as the election results came in.选举结果陆续传来，失败的情绪越来越重。
