These doubts had been gnawing at him for some time.

这些疑虑已经折磨他间了。

The farmer’s dog has been gnawing away on a bone under the table.

那农夫的狗直在桌底下啃骨头。

He was afflicted always with a gnawing restlessness.

他老是被种恼的不安情绪折磨着。