I can hear someone ( ) in the classroom.答案为singing.这是什么时态,为什

I hear someone singing in the reading room.其中singing 是什么结构呢. I sit in the front of the classroom as I can hear clearly.这句 英语改错Listen,I can hear someone in the bedroom .这句话哪里有错?Listen In the country,I can hear the birds____.填sing or singing? —Listen!I can hear Jacket singing in the next room.—It _____ i sit in the front of the classroom()i can hear clearly I sit in the front of the classroom so I can hear clearly对吗? I can hear the birds singing right there right? it is too noisy in the classroom.i can't hear my teacher ___ Who is singing in the classroom?I want to know We often hear him ______ in the classroom.A.sing B.singing C Please speak louder.Everyone in the classroom can hear you