If the bell curve for this particular subject is high and i get C6 would i get D7 instead?and for maths paper 2 some parts i never put units how would they minus?
Here's an example of marking scheme for one question posted by frekiwang.
http://sgforums.com/forums/2297/topics/438846
Further read the thread, you will find the links given by wee_ws on sample of marking scheme by Cambridge.
Best regards,
Chin Seng