any questions which appear to have been written subjectively have likely been done so deliberately. Many lecturers like to be disagreed with -- even if they do not share your point of view, it is more likely they will award your confidence than penalise you for disagreeing with them. Finally, bear in mind that if your lecturer awards you 69% they're not being mean -- a score of 69% means you've done really well, but your work hasn't quite reached first class standard. Read their feedback closely and, crucially, act on it next time.