Complex sentence: Work on the portion in the District began in 1992 and work on the paved section of the Capital Crescent Trail from Georgetown to Bethesda began in spring of 1994, but the section from Bethesda to Silver Spring was delayed due to continued debate over the proposed trolley.
Split into simpler sentences: Work on the portion in the District began in 1992 and work on the section from the District to Bethesda began in spring of 1994. The section from Bethesda to Silver Spring, however, was delayed due to continued debate over the proposed trolley.