A:ω=1,φ= π3
B:ω=1,φ=﹣ π3
C:ω= 12 ,φ= π6
D:ω= 12 ,φ=﹣ π6
当建筑物内遭遇火灾时,受困人员应该采取弯腰甚至匍匐的姿势撤离火场,这样能够有效避免吸入有害气体或被灼伤,这是因为含大量有毒有害的空气物质( )
—May I help you?You seem to be having some problems.
—________,thanks. I think I can manage.