请教一道语法题

outworldlife

The first city in the United States that (put) into effect major (plan) for (the clustering) of government (buildings) was Washington, D.C.

答案选B,原因是单数可数名词不能单独存在.但是A也应该不对,put前面的that指代 the first city put应该改为第三人称单数形式啊,请各位指点指点.

gre3333

put在这里是过去式。从后面的was可以看出。

outworldlife

了解了,谢了