A:①和③对比,证明铁钉锈蚀需要氧气
B:②中植物油的作用是防止水蒸发
C:③中铁钉的甲、乙、丙三处,丙处锈蚀最严重
D:实验证明了铁在潮湿空气中容易生锈
They will go to Beijing by train.
–_______ I like many pop stars.