Ordinary welders must hold a special welding operation certificate; If you want to learn welding technology, you need to attend the training course of welding specialty and learn the specific price theory; About three months, the difference of energy demand depends on one's own understanding and efforts. The main training of safety supervision bureau must include basic knowledge of safety.
Sophomore semester summary 300 words 1
It's fleeting, my sophomore year has passed, and I wasted another semester in the so-called bu