Complex sentence: Manned Apollo flights were suspended for 20 months while the Command Module's hazards were addressed, and development and unmanned testing of the Lunar Module (LM) and Saturn V Moon rocket continued.
Split into simpler sentences: Manned Apollo flights were suspended for 20 months while the Command Module's hazards were addressed. However, the development and unmanned testing of the Lunar Module (LM) and Saturn V Moon rocket continued.