熔断器
参考答案：
是一种简单的短路或严重过载保护电器，其主体是低熔点金属丝或金属薄片制成的熔体。
Not only _____ polluted, but _____ crowded. [ ]
A. was the city; were the streets
B. the city was; the streets were
C. was the city; the streets were
D. the city was; were the streets
燃料粒度大小对烧结矿碱度无影响。（）
