There uesd to be a lot of chemical plants in the south,but many o_英语解答

There uesd to be a lot of chemical plants in the south,but many of them have been closed or are ?be closed. A to B supposed to
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人气：206 ℃　时间：2019-10-17 08:00:57

解答

选A,to be表示将会发生的,supposed to是应该,假设的意思,虽然语法上没有错误,但意思上说不通