am：
I am a student.
I am doing my homework.
I am looking forward to going to have a dinner.
I am a girl.
I am going to my school.
is：
He is my friend.
She is a nice girl.
It is my cat.
My home is near yours.
This is my classmate.
are：
They are from China.
My parents are very nice.
You are my best friend.
There are some people in this house.
They are doing their homework.
希望能帮上您!
