请问要写到什么水平呢?如果是高中水平的,则：
Hi,I‘m kate who study in the sixth middle school. There're twenty classes in our school . I am in Class five, Grade one and there are sixty students in it. I love my school which is big as well as beautiful,and there are a great many of trees and beautiful flowers.
It is very kind of teachers to care for us. Welcome to our chool.
初中水平:
Hi, my name is Kate, and I study in the sixth middle school. There are twenty classes in our school. I'm in Class five, Grade one and there are sixty students in it. Our school is big and beautiful, and there are a lot of trees and beautiful flowers.I love my school very much.
It is very kind of teachers to care for us. Welcome to our school.
【那个你的第二句,学校有20个班级,在一年级5班,班内有60个学生.我理解成了：你们学校有20个班级,你在一年级5班,你们班内有60个学生.希望没有错.】
希望可以帮到你.