题干
Bob took a photo of his girlfriend while she _________ at the party.
A：dances
B：was dancing
C：has danced
D：is dancing
答案(点此获取答案解析）
B
Bob took a photo of his girlfriend while she _________ at the party.
A：dances
B：was dancing
C：has danced
D：is dancing
的虚部是（ ）
