"There is a Christian church and a Muslim mosque in my city."
Translation:Στην πόλη μου υπάρχει ένας χριστιανικός ναός και ένα μουσουλμανικό τζαμί.
Just for info as my answer was deemed "almost correct". In GR there is "μία" and there is also "μια". The meaning is exactly the same but "μία" is a two syllable word and is pronounced accented in "ί", while as "μια" is a monosyllable word (hence the loss of the accent mark) and is pronounce accented in "α".
Same thing goes for "δύο=two" and "δυο".
For more info have a look at this: https://en.wiktionary.org/wiki/Appendix:Greek_number_and_measurement