抱歉我迟到了——钥匙出了点问题。

Sorry I'm late - a problem ___came ___up with the keys.

我觉得非常有用，因为我不需要写或读，如果有问题出现，我就打电话给合格的老师。

I found it very useful that I did not have to write or read, and if a problem ___came ___up I just called the qualified teacher.

会议期间，出现了一个需要立即关注的意外问题。

During the meeting, an unexpected issue ___came ___up that required immediate attention.