Well I dont know if you will read this before the test since it is today - but good luck...
Tip: Read each sentence carefully. Review each answer choice. Draw a grid and eliminate obvious wrong answers. Look for parallelism, modifying issues, and verb tense. At this point you wont learn anything new but if you are patient and deliberate in your reading I am sure you will do fine.
Cheers for that m8! I leave for the centre at half 11.