test your hypothesis: how will you use the computer model to test your hypothesis? what steps will you follow? what data will you record? conduct your experiment and record your results.

what is a or b because in the question it dosent give me the answer choses that i need

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 : )

the part of the wave he is travelling on is the crest