They were part-way through the speeches when he arrived.

他到达的时候讲演已经进行一段时间了。

《牛津词典》

I happened to be at the station when he arrived.

他到达时我恰好在车站上。

《新英汉大辞典》

He asked Mrs. Medlock rather irritably when he arrived.

他抵达时，烦躁地问梅德洛克太太。

youdao

When he arrived, he walked to the desk of the chief bank employee.

VOA: special.2010.02.07

And was true of President Bush when he arrived in January of 2001.

对于布什总统来说也是,他2001年1月上任以来就是。

普林斯顿公开课 - 国际座谈会课程节选

When she arrived in Moscow, a Soviet official gave her a special travel permit, because he liked her industrial photographs.

VOA: special.2009.05.10

When he arrived back at his offices in Maryland, he sat down with Sonstegard.

FORBES: Technology

When he arrived at New York-Presbyterian, he raced to his office and changed into scrubs.

NEWYORKER: The Operator

His aunt, however, said neither of Tsarnaev's parents was in Russia when he arrived.

NPR: Aunt: Boston Bombings Suspect Struggled With Islam