The auxiliary verb haben in the present perfect tense is followed by two parallel second participles gemacht and besucht, both of which dominate the fourth case: habenneine stadtührung gema cht and habendie Parade besucht. The former uses an indefinite article and the latter uses a definite article, which is determined by the meaning of the sentence: city sightseeing stadtfü hrung is a general concept, and parade parade is a concrete concept in the sentence;

Besuch der Parade is not a sentence, but a noun phrase. Der is the second form of the definite article die, which means that the noun behind modifies the noun in front (mostly indicating all relationships, such as the mother menu of das Kochbuch der Mutter). Literally, it can be translated into: visit the military parade, which means visit the military parade in Chinese, and another example is: die? Opening hours of the library

Three things four have nothing to do with the sentences here. When a verb has two objects (double-object verbs), if the direct object is an object and the indirect object is a person, then the object representing the object is the fourth case and the object representing the person is the third case. Such as: ich schenke meinembruder (d.) einbuch (a.).