用英语介绍你的朋友、同学或老师用于向大家介绍你的同学、朋友或老师。子书30个词左右

This is my best friend Mary. She is nine years old. She usually wears a white T-shirt and a pink skirt. And she likes dancing. She usually dances with me after school.What's more, she is hard-working and often helps me with my study. We are good friends.

this is sb.