We had the duty sqn recce mate - but, as we were UK AD, 'They' had decided that we needed to know the RN's war canoes as well as various types of Bear, etc.
So, every so often, on went the slides. Once, after 10 consecutive slides of the Sverdlov, Clunk - on went slide 11. "Gizzard", asked BK of the RAF's only commissioned football hooligan, "what's that"?
"Sam Kotlin".
"No, you ar$e, it's the same bastard Sverdlov! OK chaps, on with the test"
Clunk - "Broadsword"
Clunk - "Amazon"
Clunk - "Bristol"
"Hmm, BEagle, you've obviously been studying. Well done!"
"No I haven't. Well, only a bit. Because the next one is a County, then Invincible, Rothsay, Leander and Sheffield. Same as last time - BABCIRLS! Suggest you randomize your slides, BK!"
"Oh bugger!"