Is this correct:
1-In this city the zoo is not the only place there are wild animals . Some people keep them in their apartments.
The resort to "them" is an example of anaphora. The referent of the pronoun is easily recoverable from the previous part of the text.Some people keep them in their apartments.
I underlined the nouns to which "them" may refer.In this city the zoo is not the only place there are wild animals
Keep the city in their apartments? No.
Keep the zoo in their apartments? No.
Keep animals in their apartments? Yes.
Pragmatic competence helps recover the referent of "them" from the surrounding context.
"where" is an adnominal relative adverb, the omission of which leaves the sentence intact from a grammatical point of view.In this city the zoo is not the only place where there are wild animals.