If I have an object in my hand that I do not know the Spanish word for, I would ask "¿Qué es esto?" for "What is this?". Since there is no neuter plural pronoun, how do I ask "What are these?"?
Maybe "Qué son estos?", but "estos" is masculine plural rather than neuter plural and since I don't know the word for these things, I don't know whether they are masculine or feminine.