dwell on
phrasal verbdwell on/upon something 
- to think or talk a lot about something, especially something it would be better to forget老是想着,唠叨(尤指最好应忘记的事) - So you made a mistake, but there's no need to dwell on it.你是错了,不过不必老是想着这事儿。 
 - Her mind dwelled gloomily on the future.她闷闷不乐地想着未来。 
- I don't want to dwell on this subject for too long.我不想在这个问题上纠缠太久。 
- She had learnt never to dwell on what might have been.她已经学会永远不要老想着可能发生的事情。 
- They had no time to dwell on present miseries.他们没有时间细想当前的苦难。 
 
- So you made a mistake, but there's no need to dwell on it.
- to look at something for a long time细看;凝视