Chances for PLME at Brown University:

<p>Hi,
I'm a junior in high school right now and I'm very interested in the PLME at Brown University. I want to know how to increase my chances of acceptance. NOTE: I am still a junior, so I can and WILL do whatever is in my capacity to better my chances, and I understand that I can start applying as soon as I get my grades for junior year. This is what I am currently in and do:
I am a full IB DP candidate, my course is as follows for this year:
IB Biology HL
IB Spanish HL
IB English HL
IB Math SL
IB Chemistry SL
Physics
AP Government
Theory of Knowledge
Next Year I will take IB Econimcs as my third SL class, my school offers it as a one year-course, in addition I will add Anatomy and Physiology to my schedule next year.
I am a part of these clubs:
Key Club (community service)
National Honor Society
Environmental Science Club
"Power of 100" (against bullying)
I have participated in:
JV Girls tennis
Summer Tennis camp
Volunteer work:
I volunteer every Saturday for 4 hours at the local hospital's Emergency Dept.
I do various other volunteer activities such as food drives, and set-ups at school
I am also currently looking to get involved in some sort of reaserch project in affiliation with a local University.
My ACT Score is currently a 28--I know this is low, I am working to fix that.
My Unweighted GPA (my school doesn't weight GPA's, I hear colleges look at unweighted anyways..): 3.89 ( all freshman year I took honors and all sophomore yaer I took honors and AP, I took the hardest courseloads offered at my highschool)
What do you guys think? How should I increase my chances? Any suggestions would be appreciated!!!
Thank you guys in advance, I'm sorry I know the post is long!!!</p>