易挥发出易燃、有害及刺激性气体的危险货物装卸作业现场，应保持良好通风，防止中毒和燃烧爆炸。
参考答案：对
Would you please drive more quickly? My plane will_____in twenty minutes.
I want to but safety comes first.
A．take off
B．take up
C．take down
D．take out
正常人体液进入腹腔，由哪种途径回流，保持人体动态平衡（）①毛细血管②毛细淋巴管③肠壁④腹膜
A.①②
B.②④
C.③
D.①②④
