---in the united States,St,Louis has now become the24th largest city.1.once the fourth biggest city
问题描述：
---in the united States,St,Louis has now become the24th largest city.1.once the fourth biggest city
2.it was once the fourth biggest city
3.the fourth biggest city it was
3为什么不行
答
once the fourth biggest city ---in the united States,St,Louis has now become the 4th largest city.曾经是美国第四大城市的圣路易司如今已经成为第24大的城市.应该是选1吧...因为后面的句子已经有圣路易司了,所...