Who is singing in the classroom?I want to know合为一句

who is singing in the next room 为什么who 后面要跟 is singing? listen,who is singing in the classroom?变成 are Listen!Who is singing in the next room?这里为什么要用singing Someone is singing in next room.Please go and see who it is.为什么是 who it is Everyone that I know who is like studying and singing in High School.请问这句哪错了 Who is singing in the classroom?I want to know合为一句 who is singing in the room?百度百科说这句是陈述句语序?我怎么觉得不对呀 the girl __an englishlsong in the next room is tom's sistera,who is singingb.is singingc.sangd.was singing 为什么不可以选Bthe girl （ ） an English song in next room is Toms sisterA who is singing B is singing C sang D was singing知道答案是A 但 B 错在哪 ——Listen!Who is singing in the next room?——Gina _____.（完成对话）为什么? -Who is singing in the next room.-_ must be Marie A.It B.She C.This D.There who is 什么than you at singing in your family.a,good,b,well,c,veryd,rather Who is _____than you at singing in your famliy?选择A.good B.well C.better D.best Who is going to____the singing contest tomorrow?有选择的:A.joinB.take part onC.takeD.take part in Who is singing in the classroom A SheB ItCThisD He为什么选B,而不选其他的答案? Who comes ____(one) in th exam Listen!Who ____?A.singing B.is sing C.is singing S______ is singing in the room.