Complex sentence: In WWI the British motor gunboats which won naval supremacy from the Germans on Lake Tanganyika were armed with the Hotchkiss 3 pounder and the Hotchkiss 6 pounder was adopted by the British army for the first tanks.
Split into simpler sentences: In WWI the British motor gunboats which won naval supremacy from the Germans on Lake Tanganyika were armed with the Hotchkiss 3 pounder. The Hotchkiss 6 pounder was adopted by the British army for the first tanks.