Which of the following is a part of a constitutional republic Laws are written by a king
People must obey the president.
People vote for representatives.
People cannot affect the government.

i guess that visual aids present persuasive examples to what you are presenting, some factors would be theme (does it fit with the color, information, what you are presenting), size (can you see it, is it a big enough span of data/information), and overall look of the visual aid.

hope this : )

drying towels at the beach