incumbent

the first/last/previous incumbent

第一任／上一任／前任

The incumbent president faces problems which began many years before he took office.

现任总统面临着他上任前很多年就已开始出现的种种问题。

She felt it incumbent upon/on her to raise the subject at their meeting.

她感到她有义务在他们的会上提出这个问题。