Are the girls in Changzhou BYD factory tired?

What BYD's assembly line women do is make screws. BYD does a wide range of business, such as sticking mobile phone buttons, testing mobile phone screens, polishing the back shell of mobile phones, controlling machine dispensing, mobile phone quality inspection, tablet computer quality inspection, mobile phone suppression, and mobile phone rework and glue removal. There are also front-line material workers. BYD also involves many things, such as masks, cars, mobile phones and computers. So there are many assembly lines and women workers doing a lot of things.