The phrase "belongs to" can be replaced with multiple synonyms to add variety and originality to your writing. Words such as "pertains to," "is the property of," "is owned by," and "is affiliated with" are commonly used to convey ownership or association. "Rests with," "lies with," and "resides with" are idiomatic phrases that can also replace "belongs to." A more figurative substitute would be "is a part of," which places emphasis on the idea of something being a component in a larger entity. Using synonyms helps to avoid repetition and can add depth to your writing.