Complex sentence: Chen was a trustee representing ward 21 in the Toronto District School Board as well as Board Chair\\ but resigned on August 5,2015 to run as the federal Liberal candidate for the newly established Scarborough North riding.
Split into simpler sentences: Chen was a trustee representing ward 21 in the Toronto District School Board as well as Board Chair, he has since vacated the seat. He resigned on August 5,2015 to focus on being the federal Liberal candidate for the newly established Scarborough North riding.