Answer:
to decide if your topic is too narrow or too broad
Step-by-step explanation:
Practice is a strong ally of perfection, and for this reason it is important for a speaker to train whenever possible in his speech, to become familiar with the speech, to feel confident giving his speech in front of an audience and to see if the speech is too long or too short.
Deciding whether the topic of the speech is too narrow or too broad is not a good reason for the speaker to practice the speech. This should be done while reading and reviewing what was written.