It is generally acknowledged that it depends on the zoo because sometimes the animals are loved and sometimes hated.

generally 是形容词 general（普遍的、一般的）的副词形式，表示"通常地、普遍地"。 acknowledged 是动词 acknowledge 的过去分词形式，acknowledge 意思是"承认、认可"。在这里与 is 构成被动语态，表示"被承认/被认可"。 generally acknowledged 这个短语表示"被普遍认可/公认"。