(　?。﹊n 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,為什么,A哪里又錯(cuò)了呢?

熱心網(wǎng)友

A表現(xiàn)在的狀態(tài),是不對的,可說used to be the fourth biggest cityB是修飾St.Louis的定語,只是作為插入語單獨(dú)寫出來罷了

熱心網(wǎng)友

being表現(xiàn)在還延續(xù)的動作或狀態(tài) 明顯是過去的動作 故用once

熱心網(wǎng)友

A指一直如此,不是一度如此