extemporise
vt. 当场作成
近义词：ad-lib，extemporize，improvize，improvise，
英英释义
Verb
- perform without preparation;
"he extemporized a speech at the wedding"
例句
- He had to extemporize because he had forgotten to bring his notes.他因为忘了带讲稿，只好即席发言。