( ) Go back _____your seats, Bob and Zhou Pei. A. to B. in C. on
He is my _____. A. brother B. sister C. mother
---Is she your sister? ---_____. A. Yes, she isn’t.B. No, she is.C. Yes, she is.
---Who is that girl? ---_____ is my sister. A. She B. He C. She’s
This is _____ new pen. A. anB. /C. a
Who is _____ boy? A. itB. thatC. an