我国东北的黑土地上种植的马铃薯块大、质优、淀粉含量高,这说明黑土地中哪种无机盐充足( )
A:含氮无机盐
B:含磷无机盐
C:含钾无机盐
D:含铁无机盐
下列句子中没有语病的一项是( )
—Water had got into it,and it was completely .
化简:y×yx3÷-x2y-2=____.