A:钢管与电源正极连接,钢管可被保护
B:铁遇冷浓硝酸表面钝化,可保护内部不被腐蚀
C:钢管与铜管露天堆放在一起时,钢管不易被腐蚀
D:钢铁发生析氢腐蚀时,负极反应是Fe-3e-=Fe3+
读图,判断句子对错,并修改:
What's this?It's a bird. ____