drunkenbozo, the first test was based (somewhat loosely) on the ATC hand-out they email you in the confirmation letter. The predominant questions are in relation to that file. However there were certain parts slightly left-field, if you have only been focusing on the material they send you.
Ex. " What is the distance from London to Brussel?" , "Two aircraft approaching each other head-on.." - type scenarios. "Define ILS"
General "geographical distance" between countries could be quite pivotal to brush up on. The usual speed/distance/time as mentioned previously will be involved. I thought I had done quite sufficient background re-search on NATS, yet there were still questions I was unsure of.