Complex sentence: The Royal Navy is the second largest navy in the World in terms of gross tonnage, and is in charge of the United Kingdom's independent strategic nuclear arm, which consists of four SSBN's armed with Trident D5 SLBM's.
Split into simpler sentences: The Royal Navy is the second largest navy in the World in terms of gross tonnage and is in charge of the United Kingdom's independent strategic nuclear arm. It consists of four SSBN's armed with Trident D5 SLBM's.