________ that all mountain roads were closed.

A.So became the dangerous weather

B.So dangerous did the weather become

C.So dangerous became the weather

D.Dangerous the weather became so

答案及解析： B

解析：

考查倒装句。So+ 形容词或副词放在句首使用部分倒装，借助于助动词，故选B。句意：天气变得如此的危险以至于所有的山路被关闭了。