ABZ
I see youre very young so I will take that as an excuse.
I dont know what school is like nowadays, but if you are used to being spoonfed, you have a long way to go. Sure at the college there is a certain amount of spoonfeeding, but you have to use your own initiative.
Do you really see NATS giving you distances to EU Cities. Youre going to have to use some common sense. Get an ATLAS and start having some appreciation for distances. Not exact, I am sure the multiple choice answers will all be in whole numbers divisable by 100. It will all be common sense. I would certainly complete my A-levels, and use your 1st application as a learning tool. Maybe get some kind of employment, and you will soon mature. I am not being unkind to say that you seem very immature, even for 17, and the profession that you are keen to enter, is a highly skilled professional job for highly motivated people with stacks of common sense and a huge amount of confidence.