Complex sentence: In June 2017, President Trump nominated Liu to become the next United States Attorney for the District of Columbia, which is the country's largest U.S. Attorney's office, with more than 300 prosecutors.
Split into simpler sentences: In June 2017, President Donald Trump nominated Liu to become United States Attorney for the District of Columbia. The District of Columbia houses the country's largest U.S. attorney's office, with more than 300 prosecutors.