There are plenty of words that can be used as synonyms for the phrase "are keeping". From preserving an object's condition using the word "maintaining", to safeguarding something with "protecting". "Holding onto", "retaining", and "storing" are just a few examples of other alternatives. Additionally, "maintaining possession", "sustaining", and "upholding" can also be used. Depending on the context, words like "continuing", "persisting", or even "enduring" can convey the idea of "keeping on" with something. Ultimately, the synonym used depends on the context of the sentence and the intended meaning.