电缆封堵
参考答案：是为了防止火灾延燃，电缆栈道内应每隔60米划分防火隔段。
I couldn’t help but_____very concerned about his illness when I heard he was in hospital because of heart disease.
A．to feel
B．feel
C．feeling
D．to have felt
PAD图是一种 【3】 设计工具。
