Where does the student live? | Which student are you referring to? | Is there any students living in HKG or CHI?
SELECT count ( * )  FROM Student WHERE city_code   =   "HKG" OR city_code   =   "CHI"
students living in HKG or CHI refers to WHERE city_code = 'HKG' OR city_code = 'CHI'; count of students refers to SELECT COUNT(*);