Source: https://www.reddit.com/r/languagelearning/comments/10e9o4e/how_do_you_go_from_b2_to_c1/?rdt=33298
"As an example, one of the listenings during my C2 English exam was about aquarium maintenance. WTF. That took me totally off guard. Do I know the name of every gadget, filter and air pump in an aquarium? In my native language some of them, yes. In English? Hell, no."
Reflects:
The tips from B2 to C1: Engage with diverse media