- Có t?i thi?u 02 n?m kinh nghi?m trong l?nh v?c quan tr?c môi tr??ng lao ??ng ho?c 05 n?m kinh nghi?m trong l?nh v?c y h?c d? phòng;Begin by ensuring many of the required sections have interfacing attached. If your collar can be a convertible collar that has a stand, sew the collar portion to start with. Then sew the stand, enclosing the collar