49.In the southwestern part of the United States ________ built in the last century.A) they are many abandoned mining towns B) where there are many abandoned mining townsC) are many abandoned mining towns D) many abandoned mining towns are为什么
问题描述：
49.In the southwestern part of the United States ________ built in the last century.
A) they are many abandoned mining towns B) where there are many abandoned mining towns
C) are many abandoned mining towns D) many abandoned mining towns are
为什么
答
B
答
C
如果states后有逗号可以选A D，同时A的they改成there.
如果选B，前面都是位置状语，没有主语了。
答
B where 引导定语从句 修饰 美国的西南部
然后 built in the last century. 后置定语修饰 mining towns
这句话的意思是 在美国的西南部，那里有许多建于上个世纪的遗弃的矿业城镇。
总体是个短语
答
选D
答
C) are many abandoned mining towns
主要考点就是:当介词短语前置,句子倒装.