Answer:
Tenochtitlán was an Aztec city that flourished between A.D. 1325 and 1521. Built on an island on Lake Texcoco, it had a system of canals and causeways that supplied the hundreds of thousands of people who lived there.
Stressed possesive adjective. (tuyas)
All words of the sentence are:
Las: Article, feminine, plural.
Arepas: Noun, feminine, plural.
Tuyas: Stressed possesive adjective, feminine, plural.
Son: Verb, simple present tense of "ser", plural.
Mejores: Descriptive comparative adjective, plural.