Similarly to how I remember "fly" because it sounds like the Russian word for "Moscow", I can remember this because it sounds like spatula. I don't know how it works (perhaps it's the idea of Italian people brushing their hair with spatulæ), but it does.

pennello is also "brush" and should be accepted.

I wrote spazzolino. Is it incorrect?

It only asks for "the brush" and does not specify. So I put "il pennello" as in paint brush and was marked wrong.

what is the difference between la spazzola and la pettine?

It didn't accept "La spazzola sferica con setole di metallo" :(

It didn't accept "la spatula"

Sometimes Italian is much like Spanish and sometimes not so much. I typed the "il" expecting something like "cepillo" and ended up having to delete it and type "la" instead.

I wrote "pennello" which also means brush. The sentence did not specify what type of brush so I don't understand why it is not accepted.

Why is "spazzola"'s accent on the first A instead of the O?