Complex sentence: It flourished as both a motor racing circuit and aviation centre until 1914 and the advent of World War I. Reopening in 1920 Brooklands once again became prominent in motor racing and aviation.
Split into simpler sentences: It flourished as both a motor racing circuit and aviation centre until 1914 and the advent of World War 1. Re opening in 1920 Brooklands once again became prominent in motor racing and aviation.