Listen!Who is singing in the next room?这里为什么要用singing

Listen!Who is singing in the next room?这里为什么要用singing who is singing in the next room 为什么who 后面要跟 is singing? ——Listen!Who is singing in the next room?——Gina _____. Listen!Helen is singing in the next room. listen,who is singing in the classroom? who is singing in the room? Listen!The c___ singing in the next room. Listen!There _____ someone singing in the next room . LISTEN,MARY IS SINGING IN THE NEXT ROOM.THAT__BE MARY.SHE IS Listen,Mary is singing in the next room.That ___ be Mary.She 2.Listen!Someone ____ in the next room.A.sing B.singing C.is 1..Listen!A boy in the next room.A.sings B.is singing C.sang