过去式： did 过去分词： done

do

v.做，干，办(某事);(以某种方式)做;行动;表现;(问询或谈论时用)进展，进行

aux.用于实义动词前构成否定句和疑问句;构成附加疑问句

n.社交聚会;社交活动

n.（口语）事件;（主英国口语）诈骗;（主英国、新西兰口语）宴会;（口语）必须做到的事情

相关介绍

What in the world did they think they were doing?

他们到底认为自己在做什么？

He would do well to concentrate more on his work.

他最好还是更加集中精力在工作上。

One major problem did present itself, though.

不过，确实出现了一个重大问题。