A good military speech topic may be about anything that is relevant. This may include self sacrifice, defense, commitment, appreciation of military servicemen and women and so much more.
If it is a science speech, yes
a speech is good when the topic you've brought forward involves your audience and you present it in a simpler way as possible and lastly a speech is good when you understand your topic
A good speech topic is one that interests both you as the speaker and your audience. It should be relevant, timely, and have a clear purpose or message. Additionally, a good speech topic should be specific enough to be manageable within the time frame of the speech.
accomplishment speech
Speech of mother good
world war 1
* / ===
gun control
well it depends
Black History is a good subject to create topics for a speech but it can't be a topic itself.
Anything would be a good topic so long as you do your research and know enough about it.
A good topic would depend on where you are presenting it in front of what kind of people you are presenting it to.