Final answer:
The textbook recommends organizing key points quickly and speaking spontaneously when you need to speak impromptu.
Step-by-step explanation:
When you need to speak impromptu, your textbook recommends organizing key points quickly and speaking spontaneously. This means that you should think on your feet and deliver a speech without extensive preparation or memorization. Impromptu speaking requires you to be able to think quickly, adapt to the situation, and connect with your audience effectively. It is important to be confident and maintain eye contact with the audience to engage them.