A:Kw>1×10﹣14
B:水电离的c(H+)>1×10﹣13 mol/L
C:pH>13
D:c(OH﹣)=c(H+)+c(Na+)
一个角是20°10′,则它的余角是____
The chair is under the desk.
______terrible the weather is these days!
下图示意某国城镇人口和乡村人口的变化,读图回答下列各题