I’m planning to take SAT in December again, but would they accept it?
also do they see 1st semester of senior year grade?
UC’s would accept the December SAT sitting. 1st semester Senior grades are not considered in admission decisions unless you receive a supplemental (only a small percentage of applicants are targeted).
If you want to be considered for scholarships at USC, the deadline is Dec 1 so the December SAT will not be considered. Regular application is due January 15. USC will consider 1st semester Senior grades.
As a prospective college student, all this information can be obtained on the schools admission website. Learn how to research the information.
http://admission.universityofcalifornia.edu/how-to-apply/apply-online/index.html
http://admission.usc.edu/firstyear/prospective/datesdeadlines.html