Complex sentence: German artillery frequently bombarded French positions with the new Mustard gas and made several spoiling attacks to disrupt French preparations but the French preliminary bombardment by guns, guns and howitzers and guns and howitzers began on 11 August.
Split into simpler sentences: German artillery frequently bombarded French positions with the new Mustard gas and made several spoiling attacks to disrupt French preparations. The French preliminary bombardment by guns, guns and howitzers and guns and howitzers began on 11 August.