Do you know the girl _________ is singing in the classroom?A. when B. who C. which
—What’s your mother__________ now? —She’s __________ our house.
Look, Tony __________ a delicious ice-cream over there.
—Are you from America? —__________.
— I like math very much. Do you like math? — __________.
—Is your mother _________ English teacher? —No, she isn’t. She is _________doctor.