为了防止炉膛和尾部烟道再次燃烧造成破坏，常在炉膛和烟道易爆处装设( )。
A．安全阀
B．超温报警装置
C．压力表
D．防爆门
参考答案：D
If he_____his teacher' s advice, Asafa Powell would not be the fastest man in the world.
A．didn't follow
B．wouldn't have followed
C．hadn' t followed
D．hasn' t followed
施工期的环境影响有哪几方面？
