Complex sentence: The British and Canadian troops that fought in the Rhineland suffered tremendous losses from the German artillery; this is why Montgomery decided that it should be silenced by a large-scale airborne operation, code-named Varsity.
Split into simpler sentences: The British and Canadian troops that fought in the Rhineland suffered tremendous losses from the German artillery. This is why Montgomery decided that it should be silenced by a large-scale airborne operation, code-named Varsity.