I am sad 改为复数句We are sad.
Is he happy?改为复数句Are they happy?
They are pretty改为单数句He is pretty.
We are their classmates改为单数句I am his classmate.
I am sad 改为复数句We are sad.
Is he happy?改为复数句Are they happy?
They are pretty改为单数句He is pretty.
We are their classmates改为单数句I am his classmate.