Nehru was a renowned orator. He could give many extemporaneous speeches in a single day.

尼赫鲁是一位知名的演讲家，能在一天之内做出很多即兴演讲。

If your remarks are extemporaneous, you have not prepared them in advance.

如果你的发言是即席的，说明你没有事先准备好。

At the Academy's annual Summit, Jobs gave a couple of short, extemporaneous talks to a roomful of promising young high school students.

在学院的年度峰会上，乔布斯对一屋子前途无量的年轻高中生做了几次简短的即席演讲。