A:有机物
B:无机盐
C:核酸
D:水分
①X+Y2+═X2++Y;
②Z+2H2O(冷)═Z(OH)2+H2↑;
③由Y,W电极组成的原电池,电极反应为:W2++2e﹣═W,Y﹣2e2﹣═Y2+.
可知X,Y,Z,W的还原性由强到弱的顺序是( )
— Mum, I've got ________ important to tell you.
— What's up(怎么了)?
如图,正六边形ABCDEF中,BA→+CD→+EF→= ( )