I tracked down the printer who did the original我找到了最初印请帖的印刷商

track down:跟踪追捕； 追查

It took the police several days to track down their quarry.

警方用了几天时间追查到案中目标。

I finally track down the reference in a dictionary of quotation.

我终於在引语词典中查到了那段引文。

Must have slipped her mind.她肯定是忘了

slip one's mind:忘记

He was supposed to have brought home a loaf of bread, but it slipped his mind.

他本来想带一条面包回家的，可他把这事给忘了。

常用短语:

slip up失误

slip away逃走

He can catch up.他待会就来

catch up:赶上

She walked too slowly to catch up with us.

她走得太慢，跟不上我们。