Complex sentence: The British contributed 13 divisions of the British Expeditionary Force (BEF), three of which were untrained and poorly-armed labour divisions and 22 Belgian, 10 Dutch, two Polish divisions were part of the Allied order of battle.
Split into simpler sentences: The British contributed 13 divisions of the British Expeditionary Force (BEF), three of which were untrained and poorly-armed labour divisions. Twenty-two Belgian, 10 Dutch and two Polish divisions were also part of the Allied order of battle.