Thank you for your sharing your explanations on many RC passages and logical reasoning. I've read them when I am reviewing and even lost in my studies.Congratulations and hard work pays off!
Try to improve on games! I think games is the easiest to improve and try to get as many points as you can on games. Review CC, drill question types, and review them.
Necessary assumption has to be within the scope of the argument and has weaker answer choice than sufficient assumption ACs.
Strong answer choices for sufficient assumptions as the sufficient can be fulfilled in many ways.