建筑物内发生火灾时,在起火房间内由于温度上升,气体迅速膨胀,对楼板和四壁形成的压力是()(难)
A、燃烧压力
B、轰燃压力
C、爆炸压力
D、火风压
参考答案:D
Since he joined the swimming team, he has _____ to swim across the wide river. [ ]
A. able
B. could
C. can
D. been able
能生成酮体的器官是()
A.骨骼肌
B.脑
C.心
D.肺
E.肝