能加快溶解速度的是( )
A:加热
B:搅拌
C:研细
D:使用大烧杯
如图,矩形ABCD中,AD=2AB,E、F分别是AD、BC上的点,且线段EF过矩形对角线AC的中点O,且EF⊥AC,PF∥AC,则EF:PE的值是____
- I have no money on me. How can I get home?
- Don't worry. I can some you.
求证:
读下边的经纬网图,完成下列各题。