Just an irregular plural.
According to the article at https://forvo.com/word/%D0%B3%D0%BE%D1%80%D0%BE%D0%B4%D0%B0/#ru, the audio is pronouncing города incorrectly. The article says that the genitive is pronounced го́рода (which is what the audio is saying, with an "o" sound on the first syllable = "gorada"), but the nominative plural (which is the word in this exercise) is pronounced города́ - with both of the "o's" being unstressed, they should be pronounced as "a" = "garada" You can hear this different pronunciation here:
Yes, as you can see in the link https://en.wiktionary.org/wiki/%D0%B3%D0%BE%D1%80%D0%BE%D0%B4 :
го́род • (górod) m inan (genitive го́рода, nominative plural города́, genitive plural городо́в)
Here's some correct pronunciations of the nominative plural: https://forvo.com/word/%D0%B3%D0%BE%D1%80%D0%BE%D0%B4%D0%B0/#ru