1.standing-->stand and并列两个相同成分 ,要和后面introduce保持一致
2.im 15---> im 15 years old 要么就im a 15-year-old girl,或者im at the age of 15
3.just graduated--->have just graduated 用完成强调
4.if i could study---->ii i can study if引导时间状语从句要推时态
5.In the three years of past----->in the past three years 更地道
6.But my English is not very good now.So I'd like to improve my English in this class.And very glad to see our teacher.——————>However,my english is not good enough,i hope that in the future,we can make progress in English together.Thank you.
后面有点乱了.从想去加拿大学习,到当班长,到英语不好.这之间的关系很乱,可以调整.