End of summer internship...?

<p>Hi, i'm currently a senior in high school, and i'm doing a summer internship in Shanghai, China. It's going to end in about 2 weeks.</p>

<p>I was just wondering if i should i ask my supervisor to write me a rec or some kind of feedback letter or something. How should i ask her? shes usually pretty busy, and my relationship with her is good, but not great...
Can i use the letter/rec as a rec letter when i apply to college this year?</p>

<p>Also, should i get her some kind of gift or something before i leave? There's about 7 people who i work close to/with, should i get them something too? How should i say goodbye on the last day?
The day before my last day, there's this team building dinner thing, should i say something or do something during that dinner to let them all know that i'll be leaving? </p>