Go out and get some sun, seriously. Its Year 10. All you need is like an A/B grade and thats easily achievable by attending classes and just doing your homework and listening in class, because somehow it sticks in your long term memory. Except for Maths, that shit needs some studying because its the
ONLY thing you need a strong foundation in for Year 11 and 12.
A lot of people who studied for Year 10 burnt out in Year 11 and will probably keep that attitude in Year 12.
So its great they got 100% in Year 10. But not so if they are getting like 30% in Year 11.