Complex sentence: USCIS is charged with processing immigrant visa petitions, naturalization petitions, and asylum and refugee applications, as well as making adjudicative decisions performed at the service centers, and managing all other immigration benefits functions (i.e., not immigration enforcement) performed by the former INS.
Split into simpler sentences: USCIS is charged with processing immigrant visa petitions, naturalization petitions, and asylum and refugee applications. It also makes adjudicative decisions performed at the service centers, and manages all other immigration benefits functions (i.e., not immigration enforcement) performed by the former INS.