A:①②③
B:①②④
C:①③④
D:②③④
将H2、CO、CO2、N2依次通过足量下列物质:澄清石灰水、灼热的氧化铜、浓H2SO4(注:有吸水性),最终剩余的气体为( )
求:
如图,在平面直角坐标系中,△ABC的边AB∥x轴,点A在双曲线y=5x(x<0)上,点B在双曲线y=kx(x>0)上,边AC中点D在x轴上,△ABC的面积为8,则k= ____.
①—You are Danny.
—Yes. I'm Danny.
②Look,I'm tall and fat. Who am I?
③Look at my eyes. My eyes are small and brown.
④My nose is big. My mouth is big,too.
____
下列关于黄土高原气候特征的叙述,正确的是