呼吸肌是肺通气功能的动力泵，主要由膈肌、肋间肌和腹肌组成。
参考答案：对
With the electricity________because of the road repairs, the whole building was completely dark.[ ]
A. cut up
B. cut off
C. cut out
D. cut down
煤气中毒的原因是由于人吸入了大量的二氧化硫后，使人的血液很快失去供氧能力从而导致煤气中毒
