题目内容：
机械加压送风的防烟楼梯间的余压应为（ ）Pa。
A．20～30 B．30～40
C．40～50
D．50～60
参考答案：
答案解析：
单选题：机械加压送风的防烟楼梯间的余压应为（ ）Pa。
- 题目分类：消防安全技术实务
- 题目类型：单选题
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B．30～40
C．40～50
D．50～60
B．30～40
C．40～50
D．50～60
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