_____there are a large number of chemical factories,the air is likely to be polluted
问题描述：
_____there are a large number of chemical factories,the air is likely to be polluted
A that
B where
C once
D as
答
应选B,因为本句的意思是“哪里有很大数量的化工厂,那里的空气可能就被污染”所以根据句意,应选B