Complex sentence: The two ships bombarded Trapani naval base and Favignana on 11-12 July and also provided cover for Operation Avalanche on 7 September to 14 September, when they escorted the surrendered Italian battleships and to Alexandria.
Split into simpler sentences: The two ships bombarded Trapani naval base and Favignana on 11-12 July. The pair also provided cover for Operation Avalanche on 7 September to 14 September, when they escorted the surrendered Italian battleships and to Alexandria.