空气冷却区的面积约占凝汽器总面积的( )。
A．5%～10% B．10%～15%C．15%～20% D．20%～25%
参考答案：A
根据短文内容，用括号内的动词的正确时态形式填空。
I 小题1:__________(have) a friend , her name is Linda . She is a 14-year-old girl .And she 小题2:__________(be) from England .She 小题3:________ (have) long hair. She likes 小题4:___________(watch) TV, listening to music , and so on. She has many good 小题5:__________ (friend) in China now .She loves China very much .
下列物质中，不属于空去污染物的是（ ）
A．二氧化硫
B．二氧化氮
C．氮气
D．可吸入颗粒物
