There isn't so much pollution in the coiuntry () in big citiestha_英语解答

There isn't so much pollution in the coiuntry () in big cities
that/as/which/what
是as么?是因为前面的so,还是因为比较时用as

人气：321 ℃　时间：2019-12-13 11:15:24

解答

as
不是因为so,而是因为后面不是完整的句子.不是定语或主语从句that/which/what都不对.
as in big cities,与前面比较,是简单句成分.