A:CO2→C6H12O6
B:H2O→氨基酸
C:H2O→CO2
D:O2→H2O
已知x﹣y=3,则代数式(x+1)2﹣2x+y(y﹣2x)的值是____
△H
In order to let more people pay attention to their plan, they ________ some signs on the wall.
在与异性交往时,我们要学会保护自己。对自己最好的保护是 ( )