How can two objects have different mass and volume yet have the same density?

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 : )

c because the action was the roller coaster reaches bottom of hill (action) reaction would be blood tends to drain away from head

hope this !