The phrase "through which" is commonly used to connect two clauses or phrases in a sentence. However, it can become repetitive and monotonous to use the same phrase repeatedly. There are several alternatives to this phrase that could be used depending on the context of the sentence. Some of these synonyms include "via which," "by means of which," "by which," "from which," and "on account of which." Each of these phrases has its own unique connotations and should be used appropriately to avoid confusion or ambiguity. By varying the use of these phrases, a writer can add depth and variety to their writing style.