A so it follows the story (but i guess you could also use B at the same time)
Base on my research, the reason why the Expository writing include more than just a fact, its because, it also need and evidence that could support the fact. I hope you are satisfied with my answer and feel free to ask for more if you have questions and further clarifications
The building's unique design surprised us.
3/5 is 3 out of the five whole pieces.
ex: there is one whole pizza cut into 5 slices. 3 slices out of the original 5 were eaten. how many pieces out of the whole were eaten?
-3.