extemporise
1. He has to extemporise because he has forgotten to bring his note
他因为忘了带讲稿,只好即席发言。
2. As for the eventual date for an election, Mr Aso appears content to extemporise.
由于大选之日逐渐临近,麻生流露出要临时做些准备工作的意图。