selfn.自己；本性；自我pron.我自己；你自己；他或她自己adj.始终如一的；同一类型的；性质不变的v.近亲繁殖；自花授粉self-sowedadj.自播的

1. A type of self-shield metal cored wire for hardfacing is studied in the paper.
   研制了一种自保护金属芯堆焊药芯焊丝。
2. Oil preserves metal from rust.
   油保护金属免于生锈。