Complex sentence: When the "Argonaut" returned to the UK, it was refitted and received the new 293 and 277 radars and took part in bombardment duties on D-Day, under the command of Captain Longley.
Split into simpler sentences: When the "Argonaut" returned to the UK, it was refitted and received the new 293 and 277 radars. It took part in bombardment duties on D-Day under the command of Captain Longley.