Answer:
I think it's similes.
Step-by-step explanation:
You can immediately cancel out allusions (reference to well-known person, place, or event outside the story) and hyperbole (an exaggeration, not to be entirely believed) leaving simile and metaphor. Because the word "like" shows up twice at the beginning and end- the roof came down steep and black like a cowl, their thick-leaved, far-reaching branches shadowed it like a pall- we can assume the answer is simile. Hope this helps!