这位老人虽然已经80岁了，但仍然保持着惊人的活力。

The old man, at 80 years old, still maintains amazing ___vigour.

他以极大的热情和精力投入了这个项目。

He tackled the project with remarkable ___vigour and enthusiasm.

这位老人以惊人的活力每天坚持晨跑。

The old man maintains his morning jog with surprising ___vigour every day.