- 搜標題
- 搜題干
- 搜選項
單項選擇題
當空氣中CO2量達到（）時人的呼吸有困難，超過（）時有生命危險。
A.1%/5%
B.5%/10%
C.10%/15%
D.15%/20%
A.1%/5%
B.5%/10%
C.10%/15%
D.15%/20%
