He potted at a sitting wild duck .

他射击一只栖息的野鸭。

Gallants gambled away a fortune at a sitting.

他在舞会上对女士们大献殷勤。

The job was finished at a sitting (a stretch).

这工作一下子（一口气）就做完了。

Eg: * She can eat ten hot dogs at a sitting!

她一口气吃了十个热狗。