Complex sentence: From 28 March to the end of July, of bombs were dropped in Bomber Command, which also sent sorties, with another Coastal Command, laying off Brest; the British lost three being minelayers.
Split into simpler sentences: From 28 March to the end of July, of bombs were dropped in of which delivered by Bomber Command. The command also sent sorties, with another Coastal Command, laying off Brest; the British lost three being minelayers.