Not only polluted but crowded.
A. was the city;were the streets
B. the city was;were the streets
C. was the city;the streets were
D. the city was;the streets were
网友回答
A. was the city;were the streets
B. the city was;were the streets
(答案→)C. was the city;the streets were
D. the city was;the streets were
解析：由not only...but also引导并列句且置于句首时，第一个分句要倒装。