He prefaced the diaries with a short account of how they were discovered.

他在前言中简要叙述了日记发现的经过。

He prefaced his words by a smile.

他先微笑，尔后开始发言。

He prefaced his remarks with a smile.

他先微笑，尔后开始发言。

He prefaced his remarks by an apology.

他以道歉作为开场白。

She prefaced her remarks By an apology.

她以道歉的话作为开场白。