Ⅰ、A. to be rude, made trouble,
gentleman, politer, more
responsible
B. shy, had few friends; outgoing,
go to lots of parties; confident
Ⅱ、One possible. version:
Dear Miss Yang,
Thank you for teaching us so well. Nearly 3 years has passed, but' I can still remember the first day I met you.You greeted me with a big smile. With your help, I have changed a lot. I used to be afraid to speak in class. But now I'm brave enough to answer your questions. Every time I have trouble learning English, you would offer me help. Thanks to your help, I've improved my English a lot. What's more, you make me know how to get on well with my classmates.
You are one of my favorite teachers. I will remember you forever.
Yours,
Linda