I would like to place on record my sincere thanks.

我要公开表示诚挚的谢意。

He is a wholehearted friend of mine.

他是我的诚挚的朋友。

Her mild but speaking countenance manifested a strong sympathy in the anticipated agony of the suppositious sufferer.

她那温和而诚挚的脸上假想难者预料中的难流露出极大的同情。

Please accept our sincere condolences.

我们诚挚的慰唁。