Title

I think L-R top row is sycamore, birch or elm, some kind of pine and bottom row; English oak, possibly cherry, and not sure about the other one. If you taught tree identification for 5 years I'm surprised you don't recognise any of them.

I didn’t know what they were because they’re in black and white, not to scale, and because there’s more to tree identification than just leaves (bark, scent, tree size, etc.). Also, if you can’t identify a tree with certainty when you’re teaching a class, you never guess. Don’t throw out a guess because you THINK you’re right. You should KNOW that the info you’re teaching is 100% true. It’s better to say “I don’t know, but I’m going to find it out” than it is to say “I think it’s this but I’m not sure and I just want to sound smart”. that’s just risky bullshitting.

That's fair enough but not being certain and not having a clue are two different matters entirely