Two to three.
Five or six.
Blue is my favorite color.
War can lead to many deaths.
The Patriot Act was a wise executive decision.
Between subjects and verbs.
Between two sentences or paragraphs.
As little as possible.
Be as broad and general as possible.
Always be about science.
Be something the writer is interested in.
It should be broad enough to explicate the topic/matter.
Two sentences are enough for being called a paragraph.
At least three sentences must be there.
At least five sentences are required for a paragraph.
It doesn't really matter how many sentences are there.
Sam played video games and the Internet slowed down.
Sam used to play video games for hours, that's why his eye sight has gotten weaker.
Sam bought new gaming console after Max did.