The sentence: un măr, __ mere And the options are doi and duoă Why îs the correct answer duoă?
In Romanian, there are three grammatical genders: masculine, feminine, and neuter. Neuter is kind of weird though: it's not really its own gender with its own set of endings. Instead, neuter nouns are treated as masculine in the singular form, and feminine in the plural form.
So, for example (I'll add adjectives to make it even more clear):
Masculine: un băiat bun, doi băieți buni
Feminine: o fată bună, două fete bune
Neuter: un măr bun, două mere bune
There's no good way to know when a word is neuter if you only see its singular (masculine) or plural (feminine) form. For this reason, some people recommend trying to always learn the singular and plural form of all nouns when you encounter them for the first time.