( ）in the United States,St.Louis has now become the 24th largest city.A.Being the fourth biggest cityB.Once the fourth biggest cityC.It was once the fourth biggest cityD.The fourth biggest city it was答案是B,为什么,A哪里又错了呢?
热心网友
A表现在的状态,是不对的,可说used to be the fourth biggest cityB是修饰St.Louis的定语,只是作为插入语单独写出来罢了
热心网友
being表现在还延续的动作或状态 明显是过去的动作 故用once
热心网友
A指一直如此,不是一度如此