She felt it was incumbent on herself to act immediately.
她感到立即采取行动是她义不容辞的责任。
《柯林斯英汉双解大词典》
2
Incumbent officeholders are difficult to defeat at the polls.
现任官员很难在选举中被击败。
《柯林斯英汉双解大词典》
3
The tight race is almost a duplicate of the elections in Georgia and South Dakota last month that pitted a Republican challenger against a Democratic incumbent.