sat 2010年1月真题求助一道IS
The agency reports that by rigorously enforcing state regulations,(industrial pollution has been successfully reduced to acceptable levels.)
A.
B acceptable levels of industrial pollution have been successfully reduced
C.they have succeed to reduce industrial pollution to acceptable levels
D they have succeeded to reduce industrial pollution to acceptable levels
E it has succeeded in reducing industrial pollution to acceptable levels
我选的是B ,但是答案是E,it根本无从指代啊,