Yes you can but it's easier to have one and to just focus on them (this depends on your story.) I would say you shouldn't have more than 3 because the story could become hard to maintain unless you are an experienced writer.
There certainly can be two protagonists - it gets more complicated if you have more than one main character, but there are many books with several main characters. Think Lord of the Rings and you'll see a good example of a book with multiple protagonists (and antagonists).
No, only the main characters are in the main plot. There can be many side characters or background characters in a story, too.
Yes, aslong as you describe both in great detail and make sure to make their importance noticable-I am an english teacher at a high school
Yes you can have as many antagonists as you need without getting complicated.
Yes, the story has to be about something!
The protagonist is the main character of the story. Everything evolves around him/her. Usually, in a story, the protagonist wants to reach a goal, but many obstacles are in his path to reach this goal. These obstacles can be natural (a storm, a tornado) or human. The human obstacles doesn't want that the protagonist reach his/her goal. The human obstacles are called "Antagonist". Other characters in a story are called minor characters. These characters can help the protagonist to reach his/her goal, or be simply "decorations" and do not interact with the protagonist. There can be more than one protagonist or antagonist in a story.
Yes, Komarovsky can be seen as an antagonist in Doctor Zhivago. He manipulates and takes advantage of the characters around him, causing harm and acting in self-interest.
there are more than 1 because there are more than 1 triangles on geomotry
3
No it is most certainly not in fact it is rather poor
1 litre is more than 1 pint
2 is more than 1.
Usually a 1 chapter long story, or a picture that tells a story, and is usually a romantic story of 1 or more of the characters.
Yes, 56 is more than 1.
Yes it does at first. THUG1 has a lot of levels at the start and end of story mode. THUG2 only has a few when you finish the story mode then you have to beat classic mode. I personally like THUG1 better than THUG2 because there is more to do in the game.
3 more than 2 is 51 more than 1 is 2The product of 2 and 5 is 10
There is more than referance to Goliath in the Bible, but the main story of David and Goliath is found in 1 Samuel 17.