【简答题】Listen! Joan __________(sing) in the classroom. She often __________ (sing) there.
【简答题】Listen! Joan ______ (singing) in the classroom. She often ______ (sing) there.
【简答题】Listen! Joan ________ (sing) in the classroom. She often sings there.
【单选题】Listen! Joan __________ in the classroom. She often __________ in the classroom.