—________ is that man?
— You don't know him? He is Ma Yun.
A:Why
B:Who
C:Where
D:How
给严重缺氧的病人输氧时,要在纯氧中混入5%的CO2气体,以维持呼吸中枢兴奋,这属( )
填一填
____
听下面一段对话,回答小题.
下列观点与漫画的寓意相符合的是( )